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Rec.Food.Preserving FAQ (v.7.08) Part2
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From: Eric <ericnospam@getcomputing.com> Newsgroups: rec.food.preserving Subject: Rec.Food.Preserving FAQ (v.7.08) Part2 Message-ID: <26fgmucjoq8el1o05d4p4jp57um5cig078@4ax.com> Date: Sat, 24 Aug 2002 22:12:15 -0400 Archive-name: food/preserving/part2 Posting-Frequency: monthly (on or about 20th) Last-modified: 2002/08/14 Version: 7.08 Copyright: (c) 1998-2002 Eric Decker ( and others as specified within ) Maintainer: Eric Decker <ericnospam@getcomputing.com> Rec.Food.Preserving FAQ FREQUENTLY ASKED QUESTIONS (FAQ) in the newsgroup preserving This FAQ and all its constituent parts, as a collection of information, is Copyright 1998-2002 by Eric Decker, as a work of literature. Distribution by any electronic means is granted with the understanding that the article is not be altered in any way. Permission to distribute in printed form must be obtained in writing. The removal of this copyright notice is forbidden. -------------------------------------------------------------------------- Disclaimer: No author represented in this FAQ is qualified to establish scheduled processes nor is any author a competent processing authority in the sense of 21 CFR 113.83 et alia. --------------------------------------------------------------------------- Part 2 of 6 1.2.6. [Fruit preserves] From: edecker@inforamp.net (Eric Decker) Subject: Pear preserves Wash. Cut the pears lengthwise in halves or quarters. Remove stems, core. Peel the sections. Treat pieces against oxidation with a solution of 1 tsp of ascorbic acid per cup of water. Make enough so the effectiveness of the solution is not exhausted. Make a thin or medium syrup according to taste. Syrups: Thin: 4 cups water to 2 cups sugar Medium: 4 cups water to three cups sugar Heavy: 4 cups water to 4 and 3/4 cups sugar Combine the sugar and water, bring to a boil, skim off the froth as required. If using a sweet pear use thin, medium syrup for a less sweet pear. Simmer the fruit in syrup for 2 minutes. Remove from heat. Remove the pears from the syrup; put the syrup back on to boil. Fill sterile jars with pears leaving 1/2" of headroom. Add boiling syrup, leaving 1/2" of headroom. Wipe down the jar lips with a clean damp cloth. Apply lids and bands finger tight only. Process in Boiling-Water Bath: Pints for 20 minutes, quarts for 25 minutes. These preserves can be enhanced by the addition of whole cloves, caraway seed or cardamon seed prior to filling with boiling syrup. 1.2.7 [Marmalade] From: Patricia Hill . My recipe for blood oranges or for any of the citrus fruit marmalades is easy. Citrus marmalade Use lemon, limes, grapefruit, kumquat, oranges, tangerines, ugly fruit, tangelos Mix the fruit if you please or keep separate. Cut the fruit in halves or quarters and add water to barely cover. Simmer for 1 1/2 hours, adding water as needed. Remove the fruit from the water. Cut into thin shreds, chop or however you like it. I like thin shreds and find it is easier for me to do it AFTER cooking. My sister-in-law likes to cut it BEFORE cooking. Add the fruit shreds back into the water. Measure the fruit and water mixture. For every cup you have add 3/4 cup sugar Cook over a hot flame until it reaches the jelly stage. Put in clean jars and seal. After it has jelled, you can add a little flavor. Lime marmalade with a little Club Raki (a licorice flavored liquor) is great. Lemons with a bit of scotch is good. Orange with a little Kirsch. This makes a firm marmalade so you can actually dilute it a little. If you want more flavorings, add them to the pot before it jells. Once we went to the store and bought some of every different type of citrus fruit they had. We cooked each fruit in a separate pot. After cutting we mixed the shreds in all sorts of combinations. We made some chunky and some thin shred. We put all sorts of flavorings in. They were all good. 1.2.8 [Tea jelly.] from Michael Teifel : I made a half litre Earl Grey tea 4 times stronger than normal. And I simply added 500 grams of a commercially available sugar/pectin mixture and followed the instructions for making jelly out of juices. It tastes real good, nearly the same taste of the jelly from the mail order tea shop I tasted before. The next time I will reduce the amount of sugar so that the tea flavour will be stronger. for a second batch: I made 250 ml of green gunpowder tea with mint flavour (4 times stronger, it means 4 times more tea, not 4 times longer brewing). Then I added 150 grams of a 1:2 mixture of the sugar/pectin box (1:2 means that you have more pectin and less sugar in the mixture, so the jelly results in more fruity flavour) and added a few pine nuts. (This tea is my favourite, in Tunisia it is very common drink: chinese green tea with mint and pine nuts.) Then I followed the instructions, and it gave a very good tea jelly with a fresh flavour of mint! Add 1 TB of lemon juice for each liter. 1.2.9 [Flower jellies] >From Bess Halle : Basic flower jelly Make an infusion from edible flowers. 1 pint of flowers to 1 pint of boiling water. Most flowers have a bitter bit where the petal joins the flower so you must cut that part off. I use scissors and just trim the petals of flowers, leaving the points attached. (though once I actually snipped the points off 2 quarts of rose petals.... tedious beyond belief!) 2 C flower infusion 1/4 C lemon juice 4 C sugar 6 oz liquid pectin *optional; few drops food coloring Mix infusion, lemon juice and sugar in stainless steel or enamelware pan. Bring to hard boil you can't stir down. Add liquid pectin and return to hard boil. Boil at this temp. 2 minutes. Pour immediately into hot sterilized jars and seal. Turn jars upside down for 5 minutes and revert [or process for 5 min in waterbath]. Makes 4-4.5 cups of jelly. I've found liquid pectin works better with flowers (and herbs) than the powdered kind. You CAN make jellies with flowers and juice and I often make an apple mint jelly with apple juice and apple mint. My favorite herb combination, though, is lemon mint, made with 1 cup lemon verbena infusion and 1 cup spearmint. I never use the food coloring because I like the pale yellow and gold and pink and ruby colors. P.S. The word from the wine making group (where I first got the idea to make honeysuckle jelly) is to wash the blossoms first. This is probably a good idea because I made a batch of honeysuckle jelly over the weekend and there was an awful lot of pollen in the flowers. The jelly tasted like honey, btw, and quite good...not at all lemony, but not enough of the actual honeysuckle flavor I was aiming for. I'll probably increase the proportions next time. Here's another rose petal jelly recipe which makes more jelly. 2 quarts rose petals **see note below 2 quarts water 1/4 cup lemon juice 7 cups sugar 6 oz liquid pectin Boil petals in 2 quarts of water with the lid on, till 1/2 liquid is gone. Measure out 3 cups liquid. (save the remaining cup!!) mix with lemon juice and sugar. Bring to rolling boil. Add liquid pectin (this will be 2 packages of the liquid certo brand) and bring back to hard boil. Boil 2 minutes and pour into hot sterilized jars. Seal in preferred manner. I use the little 4 oz jelly jars so that I can give away a lot. This makes about 15 little jars. The remaining cup can be mixed with a 1 cup infusion of a favorite herb like mint or lemon balm and used in the previous recipe. I also boiled a cinnamon stick in with the jelly-making part (not the first boiling of petals) I think because I heard of a restaurant called Cinnamon Rose and the name stuck. Anyway, at first the cinnamon seemed a little strong. A friend said the jelly tasted like the apple pie from heaven. BUT after opening a sealed jar a few days later I DID detect both the rose and the cinnamon flavor. Be sure to discard the cinnamon stick before bottling. **I've used less and I've used more, so the exact proportions probably don't matter. In fact, even when I pick them at night when I get home from work, and they have little scent, cooking them brings it out a lot. Just remember, for a good red color you will need some red roses and also remember.. ..the rose brew will stain your hands, your sink, your clothes!!! 1.2.10 [Canning Cake] Not Reccomended. Be safe - freeze or "use a recipe which contains enough sugar or alcohol" to inhibit bacteria. 1.2.11 [Canned Bread 101 ] The information following is presented as Canned Bread 101. The data is copyrighted as noted. Specific permission has been given for its replication here in RFP FAQ. See Part 1 of RFP FAQ for further details of usage regarding Copyright information in this FAQ. Special thanks go to Fadi M. Aramouni for providing both the information and permission for inclusion in the RFP FAQ. ------------------ begin Canned Bread 101 ----------------------- Journal of Food Protection, Vol. 57, No. 10, Pages 882-886 Copyright, International Association of Milk, Food and Environmental Sanitarians Growth of Clostridium sporo genes PA 3679 in Home-Style Canned Quick Breads FADI M. ARAMOUNI*I, KARIM K. KONE2, JEAN A. CRAIG’ and DANIEL Y. C. FUNG2 ‘Department of Foods and Nutrition and 2Department of Animal Sciences and Industry, Kansas State University, Manhattan, Kansas 66506-1407 (Received September 10, 1993/Accepted April 4, 1994) ABSTRACT The safety of a home-style canned quick bread was investigated using spores of Clostridium sporo genes putrefactive anaerobe (PA) 3679. Baking was done at 177 C for 30, 40 and 50 min, at l91 C for 45, 50 and 55 min, and at 204 C for 40, 45 and 50 min. Products were analyzed for pH, water activity (a) and vacuum level. The microbial quality of the products was determined before and after baking. Of the products baked at 177 C, some were stored for 90 days at room temperature (23 to 25 C) or in an incubator at 35 C to study their shelf-life. Inoculated and endogenous vegetative cells and their spores were counted before and after baking and after storage using Fungs Double Tube method. Results showed germination of endogenous spores in uninoculated products after baking at 1770C for 30 min and storage at 35 C for 90 days. Survival of inoculated C. sporogenes PA 3679 was detected for all baking and storage treatments. Further work is recommended to determine safe processing procedures for this type of product. Key Words: Clostridium sporo genes PA 3679, home-canned breads, botulism. Home-style canned quick breads have been featured in popular magazines and promoted through mail order brochures and specialty shops. They are typically manufactured by small home-based operations and the process consists of oven-baking a batter in a wide mouth glass jar. Once baked, the jars are removed and immediately covered with a two-piece lid. As the product cools, a hermetic seal is created. The jars undergo no further heat treatment and are stored at room temperature until purchase and consumption. Two commercial samples purchased from a local gift shop exhibited pH values of 7.2 and 7.4, and a of 0.95. Such conditions coupled with favorable temperatures and the absence of a chemical preservative could lead to the survival and growth of Clostridium botulinum and production of toxins in the jars. Dack (4) reported that white bread dough with an initial pH of 5.4 and 37% moisture inoculated with spores of C. botulinum prior to baking and hot sealing developed toxin after 6 months of storage. Although C. botulinum is the most critical microbial hazard in canning, many inoculated pack studies used C. sporo genes PA 3679 as the test organism. Clostridium sporogenes PA 3679 is a spore-forming putrefactive anaerobe whose spores are more heat-resistant than those of C. botulinum and its testing in such studies is safer because this organism is non-pathogenic. The objective of this study was to investigate the safety of a home-style canned quick bread by inoculating the product with spores of C. sporogenes PA 3679 and challenging survival and growth of the organism under different baking treatments and storage conditions. MATERIALS AND METHODS Quick bread formulation. A banana nut bread recipe was adapted from a professional baking book(5). It consisted of pastry flour (700 g), sugar (280 g), baking powder (35 g), baking soda (4 g), salt (9 g),chopped walnuts (175 g), eggs (280 g), banana (700 g) and shortening (230 g). Dry ingredients were mixed together. All liquid ingredients were combined with the shortening and added to the dry ingredients while mixing in a HobartTM mixer (Hobart Manufacturing Co., Troy, OH). Portions of batter (250 g) were placed in a wide-mouth, pint-size glass jar and assigned to either a non-inoculated or inoculated group. For inoculated samples, the batter was put in a StomacherThi bag and transferred to the room assigned for microbiology work where 1 ml of the spore-inoculum (to be described) was aseptically dded and the bag was stomached for 2 min in the StomacherrM (Tekmar, Cincinnati, OH). After stomaching, the bag was placed back in the jar and was cut to the jar size before baking. Baking the batter in the StomacherrM bag did not result in any change in the temperature profile at the center of the cakes when compared to baking without the StomacherTM bag. The bag remained intact after baking. Baking treatments and storage conditions. A preliminary study showed baking at 177 C (350 F) for 30 min and at 204 C (400 F) for 50 min to be respectively the minimum and maximum treatments that would result in an acceptable product. Acceptability, defined as any product that was not underbaked (grayish crust, doughy) or burned (black crust, dry), was determined by a consensus of four taste panelists. Gisslen (5) recommended baking of the product at 1910C (3750F) for about 50 min. However, given the possibility of temperature gauges and human preference as to degree of doneness, different baking treatments with regard to product acceptability were investigated: baking at 1770C for 30, 40 and 50 min, at 191 C for 45, 50 and 55 min and at 204 C for 40, 45 and 50 min. Baking was done in a rotary type Hearth oven (National Manufacturing Co., Lincoln, NE) calibrated with a mercury thermometer and preheated to the desired temperatures. Baking times were measured from the time the oven was equilibrated to the desired temperature. Because use of thermocouples was not possible in the rotary oven, product temperature at the center of the bread was monitored in representative jars by inserting a mercury thermometer in the batter and taking readings through the oven’s glass window at 10 min intervals. After baking, the jars were immediately sealed and allowed to cool at room temperature (23 to 25 C). Because of their greater acceptability by preliminary evaluations of taste panelists, samples of products baked at 177 C were stored for 90 days at room temperature (23 to 25 C) or in a LablineTM incubator (Labline Co., Chicago, IL) at 35 C for extended evaluation. The latter storage condition was chosen to mimic extreme summer weather conditions that would result in temperature abuse of the product. Vacuum level, pH and A,a Vacuum level inside the jars was measured using a Ametrex U.S. Gauge Division vacuum gauge (Metek, Sellersville, PA). With an AccumetlM pH meter (Fisher Scientific Co., Pittsburgh, PA) final pH of the bread was measured using a suspension of 10 g sample mixed with 90 ml of distilled water. Water activity of the center portion of the bread was measured using an AquaLab Model a~ meter (Decagon Devices, Inc., Pullman, WA). All readings were taken in duplicates. Microbiological study. Stock culture and spore harvesting. A stock culture of C. sporogenes PA 3679 American Type Culture Collection (ATCC) 7955 maintained in cooked meat medium (Difco Laboratories, Inc.) was used in this study. The culture was obtained from the Food Microbiology Laboratory culture collection of Kansas State University (Manhattan, KS). One-tenth milliliter of the stock culture was transferred to a tube containing 10 ml of sterile cooked meat medium (Difco) and the tube was placed in an anaerobic jar with GasPak Plus (BBL Microbiology Systems, Cockeysville, MO) and incubated at 37 C for 18 to 20 h. This procedure was repeated three times to insure active growth of viable vegetative cells of C. sporo genes PA 3679. After the third incubation, a loopful of the suspension was streaked onto Tryptose Sulfite Cycloserine (TSC) agar plates (1). The TSC agar consisted of Shahidi-Ferguson-Perfringens agar base (Difco) supplemented with 8% (vol/vol) filter-sterilized solution of D-Cycloserine (400 j.tglml final concentration). Streaked TSC agar plates were placed in an anaerobic jar, which was set as described previously and incubated at 37 C for 18 to 20 h. Following incubation, an isolated colony, typically round, black and smooth, 0.5 to 1.0 mm in diameter, was tested biochemically using the diagnostic kit of RapID ANA II system (Innovative Diagnostic Systems, Inc., Norcross, GA). One isolated colony was also transferred to 10 ml of fresh cooked meat medium in a test tube, which was vortexed for 5 s (high speed). The suspension was then transferred (2 ml/tube) to five tubes containing 10 ml fresh cooked meat medium. These tubes were incubated anaerobically at 37 C for 18 to 20 h then the tubes were removed and kept in refrigerator at 40C as stock culture. With the purified stock culture, spores were harvested according to the method described by Vareltzis et al. (11), in which the stock culture is added to fluid thioglycollate medium (FTG), heated, cooled and then incubated overnight. The FTG medium is then added to the sporulation medium and incubated again for 10 days rather than 7 days as done by Vareltzis et al. (11), since preliminary studies indicated it resulted in higher recovery of spores. Spores were harvested by a series of centrifugation and resuspension steps and kept in freezer. Prior to use they were thawed for 1 to 2 h at room temperature. Spore titer determination and inoculum preparation. After thawing, spores were homogenized by shaking the bottle up and down about 5 to 8 times. One milliliter of this homogenized spore suspension was then serially diluted in 99 ml sterile phosphate buffer to obtain the desired inoculum level (ca. 106 colony forming units (CFU)Iml) to be used for the inoculated group. The spore titer was determined by serially diluting 1 ml of spores in phosphate buffer. Each dilution was then tested in duplicate using Fungs Double Tube (FDT) method (1). Presence of black colonies in the FDT indicated germination of spores in the plating medium (TSC agar) and such colonies were referred to as viable spores of C. sporo genes PA 3679. One black colony was picked with a needle and transferred in a buffer solution. This solution was then used to identify the colony with a RapID ANA II diagnostic kit (Innovative Diagnostic Systems). Count of viable spores of C. sporogenes PA 3679 was determined during a preliminary study by two detection methods, direct agar plating and FDT, using TSC agar and brain heart infusion agar (BHI) supplemented with 0.05% ferric ammonium citrate and 0.1% sodium sulfite (Difco). The preliminary study showed that TSC agar in the FDT system recovered higher numbers of C. sporogenes PA 3679 and was, therefore, used for enumeration of the organism in this research. If present in the FDT, Clostridium perfringens would also show black colonies, which within the same incubation period are much larger than those formed by C. sporo genes PA 3679 (<1 mm in diameter). Regardless of size, any black colony in the FDT using TSC agar was presumptive Clostridium and since the inoculum was C. sporo genes PA 3679, blackening was associated with this organism in inoculated samples. In non-inoculated samples, blackening was associated with Clostridium-like organisms and biochemical tests using RapID ANA II kit (Innovative Diagnostic Systems) were performed to identify black colonies observed in FDT prepared from non-inoculated samples. Bread sampling and testing of samples. Product sampling was done by aseptically removing 25 g of unbaked or baked bread samples and diluting in 225 ml sterile phosphate buffer in a stomacher bag with filter. The sample was stomached for 2 min using a Stomacher 400Th1 (Tekmar). The suspension was serially diluted and 1 ml of each dilution was used for microbial analyses(1,2). Eight samples were collected before baking and analyzed for their microbial quality. Eight samples were also collected from each baking treatment for microbial analysis. The experiment was replicated twice and all samples were analyzed in duplicates. Samples were either uninoculated or inoculated with spores at a level of I0~ CFU/g and were tested for total aerobic plate count (APC) and C. sporo genes PA 3679 count before and after heat treatment at 177 C (350 F), 191 C (375 F) and 204 C (400 F). After baking, jars were allowed to cool at room temperature for several hours (about 8 h) before sampling and microbial analysis. In the shelf-life study only bread baked at 177 C was stored for 90 days and used to evaluate for APC and C. sporogenes PA 3679. Aerobic microorganisms in the sample were counted using plate count agar (PCA) for APC (2). All agar plates as well as FDT (a self-contained anaerobic system) were incubated aerobically, with PCA plates at 32 C for 48 h (2) and FDT at 37 C for 10 h or longer (1). RESULTS AND DISCUSSION Physical and chemical measurements. The heating profile indicated that temperatures at the centers of the breads reached 106, 107 and 108 C for baking temperature set at 177, 191 and 204 C, respectively, after 50 min in the preheated oven (Table 1). Although temperature increased at a faster rate for the more drastic baking treatments, final internal temperatures were not significantly different (P>0.05). Vacuum level in the jars averaged 25.0 min of Hg for all treatments; a ranged from 0.95 to 0.93 and pH from 7.6 to 7.9 (Table 2). TABLE 1. Heating profile at center of quick breads*. Oven temperature** (0C) Batter temperature*** (0C) Baking time (min) 34 10 70 20 177 94 30 106 40 106 50 46 10 78 20 191 96 30 106 40 107 50 65 10 94 20 204 101 30 106 40 108 50 * Breads baked in pint-size, wide-mouth glass jars. ** Rotary type Hearth oven, preheated to designated temperature. *** Average of three readings. TABLE 2. pH and a of quick breads. Oven temperature**( 0C) pH* a ** Baking time (min) 7.7 0.95 30 177 7.9 0.95 40 7.7 0.95 50 7.7 0.94 30 191 7.9 0.94 40 7.7 0.94 50 7.8 0.94 30 204 7.7 0.93 40 7.6 0.93 50 * 10 g sample mixed with 90 ml of distilled water and the pH read using an AccumetTM pH meter. ** Small center piece section of a baked bread read in an AquaLab, Decagon a~ meter. Microbiological study before storage. Microbial quality of samples before baking. Uninoculated and inoculated samples with APC of 4.08 and 4.24 log10 CFU/g, respectively, were not significantly different (P>0.05). Before baking, black colonies were not detected in uninoculated samples. However, black colonies were detected in inoculated samples, which had C. sporogenes PA 3679 at level of 3.23 log10 CFU/g, immediately after inoculation. Microbial quality of samples after baking and before storage. After baking, uninoculated and inoculated samples had APC at non-detectable levels. Similarly, after storage at room temperature and at 35 C for 90 days, counts were still non-detectable by our methods (data not shown). These results indicated that vegetative cells of non-sporeforming microorganisms were either irreversibly injured or totally destroyed by the baking treatments applied. Levels of C. sporogenes PA 3679 in bread samples after baking. In uninoculated samples, black colonies were not detected before baking. Following all baking treatments, no black colonies were detected in any of the uninoculated samples either (Table 3), suggesting no activation of endogenous spores of clostridia prior to storage. In inoculated products, counts of C. sporo genes PA 3679 were significantly reduced (p>O.OS) for all baking treatments with the exception of 191 C for 45 min (Table 3). Reductions from the initial load of 3.23 log10 CFU/g generally ranged from 1.24 to 1.52 log, with the 177 C, 50 min treatment unexpectedly resulting in the lowest count (<1 log10CFUfg). The reductions in levels of C. sporo genes PA 3679 were not significantly different (P>0.05) among the baking treatments of 177 C for 30 and 40 min, of 191 C for 50 and 55 min and of 204 C for 40, 45 and 50 min. These data seem to support the heating profile study at the center of breads, which showed no significant difference (P>0.05) among the ultimate internal temperatures after baking treatments. Inconsistencies in survival rate of spores for different baking treatments (higher counts after 50 min of baking at 204 C than at 177 C) could be partly due to errors in enumeration, because of the nonhomogeneous nature of the product or to faster setting of the dough at higher baking temperatures, providing better protection to the spores from heat effects in the surrounding environment. Although these treatments reduced the level of inoculated spores of C. sporo genes PA 3679, they did not completely destroy them in the baked products. Whether or not endogenous spores in the products were totally destroyed by the temperature-time combinations used in this study was not certain. Storage studies should elucidate the existence of surviving spores. Only uninoculated and inoculated products baked at the low temperature (177 C) were further investigated during the storage study, because these products were more desirable from a consumer acceptance standpoint. Microbiological study after storage. Levels of Clostridium-like organisms and C. sporogenes PA 3679 in bread samples baked at 177 C and stored for 90 days at room temperature (RT). Uninoculated products baked at 177 C for 30, 40 and so min (Table 4) initially contained undetectable levels of Clostridium-like organisms. When stored for 90 days at RT the levels of Clostridium -like organisms were still undetectable (Table 4). Therefore, with respect to C. botulinum and other sporeformers, these products would be safe for human consumption if the initial spore levels are low and if they are stored at room temperature (23 to 25 C) or lower for no longer than 90 days. Clostridium sporo genes PA 3679 were detected in inoculated products stored at RT for 90 days and counts were 2.29, 1.71 and <1 log10 CFU/g in products baked at 177 C for 30, 40 and 50 min, respectively, (Table 4). If present in home-canned quick breads at the inoculation level (3.23 log10 CFU/g), endogenous spores will resist low temperature baking. The significance of this finding on product safety needs to be further investigated. Levels of C. sporogenes PA 3679 in bread samples baked at 177 C and stored for 90 days in the incubator at 35 C Uninoculated samples. Clostridium-like organisms counts obtained for uninoculated products stored in the incubator at 35 C were significantly higher (P>0.05) for the 30 min baking treatment (2.19 log10 CFU/g) than counts obtained for similar products stored at RT (Table 4). Several gassy jars (about 50%) from the same treatment (177 C for 30 min) were found and had to be autoclaved and discarded before 90 days. Counts were determined only using the remaining jars and may not totally reflect actual levels of C. sporo genes PA 3679 in these products. For uninoculated products baked at 177 C for 40 and 50 min, when stored for 90 days in the incubator at 35 C the levels of Clostridium-like organisms had remained at non-detectable levels. These data show that 35 C was more favorable to repair and germination of injured endogenous vegetative cells or their spores. This incubation temperature ranges in the optimum growth temperature range (35 to 42 C) for C. sporo genes PA 3679. Product prepared and stored under these conditions may not be safe to consume. Gombas (6) reported that low or inefficient heat treatments often result in survival of spores of clostridia, and their subsequent germination and growth in food systems. Inoculated samples. As expected, most inoculated products stored in the incubator at 35 C were gassy and spoiled even faster than similar products stored at room temperature. Several gassy jars, from the 30 (about 80%) and 40 (about 75%) min treatment, which could not be kept safely until end of storage period were autoclaved and discarded. Therefore, counts were determined only using the remaining jars and may not totally reflect actual levels of C. sporo genes PA 3679 in these products. In inoculated products, counts of C. sporo genes PA 3679 were <1 log10 CFU/g after baking at 177 C for 50 min (Table 4). Counts of C. sporo genes PA 3679 remained at levels of <1 log10 CFUIg when stored for 90 days at room temperature and 35 C, respectively, (Table 4). The ability of spores to repair is related to factors, such as composition, pH, and a of the medium (6). These factors are also dependent upon the intensity of heat injury, structure of spores and storage conditions, particularly storage temperature and sodium chloride (NaCl) (6,7). Heat resistance of spores can be affected by various factors including spore structure, composition and pH of the sporulation medium (6,7,10). TABLE 3. Counts (log10 CFU/g) of viable vegetative cells of C. sporogenes PA 3679 in bread samples before and after baking. Samples Before baking After baking Baking temp. 177 C 191 C 204 C Baking time (min) 30 40 50 45 50 55 40 45 50 Uninoculated <1 <1 <1 <1 <1 <1 <1 <1 <1 Inoculated 3.23a 1.99c 1.77c <1 2.99a 2.21c 1.75c 1.83c 1.99c l.71c Eight samples studied; two replicates; FDT plating in duplicates. a.b.c Means with same superscripts are not statistically different (P>0.05). TABLE 4. Counts (log10 CFU/g) of viable vegetative cell of C. sporogenes PA 3679 of bread baked at 177 C and stored for 90 days at RT and at 35 C. Uninoculated Bake Time Before bake After bake After storage RT 35 C 30 min <1 <1 <1 2.19c 40 min <1 <1 <1 <1 50 min <1 <1 <1 <1 Innoculated Bake Time Before Bake After Bake After Storage RT 35 C 30 min 3.23a 1.99b 2.29b 1.73b 40min 3.23a 1.77b 1.71c 2.59b 50 min 3.23a <1 <1 <1 Eight samples studies; two replicates~ plating or FDT in duplicates. a,b,c Means with same superscripts are not significantly different (P>0.05). From a food safety standpoint, results of this study showed that inadequate heat treatment (177 C for 30 min) of this type of product coupled with favorable storage conditions (35 C for 90 days) could lead to a health risk from consumption of these foods. The significance of the survival of inoculated C. sporo genes PA 3679 for all baking and storage treatments evaluated needs to be further investigated. Baking at a temperature of 177 C, even though resulted in highly desirable product appearance, did not result in a safe product (totally free of inoculated Clostridium after storage) for human consumption, especially when baked products were stored under conditions (35 C ), which favor spore germination. High baking temperatures (191 and 204 C) were not usually desirable from a consumer acceptance standpoint because these temperatures affected the texture and appearance of the products. During these treatments, excessive crust formation occurred after 55 min baking and this would affect consumer’s acceptability, even though desirable to enhance the microbial quality of the products. The standard procedure for home-canned quick bread (5) recommends baking at 191 C for 50 min. This treatment resulted in non-detectable levels of sporeformers in uninoculated breads after 8 h of storage at room temperature. An extended storage study of this and other temperature-time combinations will be of critical interest to determine safer baking and storage procedures for this type of product. REFERENCES 1. Au, S. M., Fung. D. Y. C. and C. L. Kastner. 1991. Comparison of rapid methods for the isolation and enumeration of Clostridium perfringens in meat. J. Food Sci. 56:367-370. 2. American Public Health Association. 1985. Standard Methods for the examination of dairy products. 15th ed. 3. Anderson, K. L. and D. Y. C. Fung. 1982. Double-tube anaerobic system for food microbiology. Food Technol. Abst. 163. 42nd Annual lET Meeting, Las Vegas, June 22-25. 1982. 4. Dack, 0. M. 1953. Food poisoning. University of Chicago Press.. Chicago, IL. 5. Gisslen. W. 1985. Professional Baking. John Wiley & Sons, New York, NY. p. 94. 6. Gombas, E. D. 1988. Bacterial spore resistance to heat. Outstanding symposia in food science and technology. Overview of bacterial spore resistance in food systems. Food Technol. 11(42):86-134. 7. Hutton, T. M.. M. A. Koskinen and J. H. Hanlin. 1991. Interacting effects of pH and NaCI on heat resistance of bacterial spores. I. Food Sci. 56:821-822. 8. Minoru, V., R. S. Fujoka and F. A. Hilmer. 1965. Method for obtaining cleaned putrefactive anaerobe 3679 spores. J. Bacterial. 89:929-930. 9. Ogg, J. F., S. Y. Lee and B. J. Ogg. 1979. A modified tube method for the cultivation and enumeration of anaerobic bacteria. Can. I. Microbial. 25:987-990. 10. Pang, K. A.. P. A. Carroad and A. W. Wilson. 1983. Effect of culture pH on D value, cell growth and sporulation rates of PA 3679 spores produced in anaerobic fermentor. J. Food Sci. 48:467-470. II. Vareltzis, K., M. E. Buck and R. G. Labbe. 1984. Effectiveness of a betalains/potassium sorbate system versus sodium nitrite for color development and control of total aerobes, Clostridium perfringens and Clostridium sporo genes in chicken frankfurters. J. Food Prot. 47:532-536. --------------------------- end of Canned bread 101 -------------------------- More on Canned Bread .... From: Bruce Carpenter My day gig is as a chemist and I looked very closely at the study that everyone is quoting. You must read all of it very closely. They found no detectable bateria after 3 months in a quick bread in a jar. The only time they did find bateria was when they put it in there to start with. The only logical conclusion from this is that the processing does not kill all of the harmfull bateria if it is present to start with. This is only one study and the conclusion the researchers reached is that more study was needed. So - it is dangerous ? - probably not very if you start with clean high quality ingredients. Is it smart ?? probably not - the parameters seem to be quite tight and the risk possibly high for such a small return. Since I save so much freezer space by canning everything else in sight all of which have excellent track records and safety guidelines ) I choose to put all of my breads up in the freezer and thus eliminate any risk. 1.3. GENERAL INGREDIENT QUESTIONS 1.3.1 [why do some recipes call for a little butter/margarine?] From: Anna Welborne. My dad always told me it kept the foam quantity down. That seems to be pretty much true, as I tried leaving it out of the strawberries this last summer, and had more foam. [BTW, for a beginner, cutting down on the foam is helpful. Less foamy jam gives a more accurate reading for your candy thermometer; too much foam is hard for a beginner to control.] From: Eric Decker. Let the jam rest after cooking. Now the scum can be easily skimmed off. Adding butter will foul the flavour to a degree you may or may not like. 1.3.2 [Sugar] Unless specified otherwise, sugar is granulated sugar. Dissolves easily, easy to pour and measure, and all the recipes are calibrated to its volume to weight. prograftaker@hotmail.com (Prograf) writes: what are the precautions I should take when storing white sugar for long periods of time? Is there a way to keep it from getting hard? I've checked the FAQ but couldn't find any information about it. [ thank you for your question. The info is NOW in the FAQ - ED] For longggggg term storage of sugar you can use honey rather than refined sugar. Honey needs to be stored in food grade poly pails. Guard against water penetration. If you wish to keep white sugar from lumping you will need to keep it absolutely and perfectly sealed from moisture. Use poly food pails and seal well to keep moisture out. Sugar has an immense affinity for a water molecule. If you wish the flavour of refined white sugar there is another way. Make a 50% solution of sugar ( use filtered or distilled water ) and bottle it off. Yeah I know it is sugar but if you want to preserve it for a long time you will need a vacuum. Oxidized sugar solution is yucky. You should Pressure Can it to exhaust the jar. 50% sugar solution doesn't need pressure but by using a pressure canner you can get the high vacuum that BWB cannot produce. For shorter term storage you can store 50% sugar solution in gallon bottles of the type used for laboratory reagents. Typically the glass is dark brown [ mandatory imho] and the stopper has a plastic seal [ highly recommended ] not cardboard. Using a funnel, fill right up to the narrow neck. Leave at least 1 inch for expansion. Make sure there is no sugar solution around the rim - wipe it with a clean damp cloth to be sure. The stoppers are equally clean and used straight from a pot of lukewarm water. Apply the stopper tight. Store in a cool, dry dark place. How to get a 50% solution? Weight of sugar and water to make one gallon. US gallons: To make a 50% solution put 1,892 grams of sugar into a pot with 3,785 grams of water. Imperial gallons To make a 50% solution put 2,272 grams of sugar in a pot with 4,545 grams of water. Note: It will be more than one gallon but by working this way you get the correct solution. You WILL need to heat the solution to get that much sugar to dissolve. Do not overheat or you will scorch the sugar and induce a bad taste which will magnify with time in storage. The idea behind making a defined solution is you know exactly its strength which will allow using it in nearly any recipe. 1.3.4 [I need some good sources for pectin] Bulk pectins, low sugar pectins, citric acid, from Dirk W. Howard : Pacific Pectin Products/ P.O. Box 2422/ 40179 Enterprise Dr., 7B-D/ Oakhurst, CA 93644 (209) 683-0303. Low sugar pectin, from Sandy Fifer : Pomona's Universal Pectin/ Workstead Industries/ P.O. Box 1083/ Greenfield, MA 01302 (413) 772-6816. Another source for bulk pectin, from both Zlotka and Kai : Home Canning Supply & Specialties/ PO Box 1158/ Ramona, California 92065 (619) 788-0520 or FAX (619) 789-4745. 1 (800) 354-4070 for orders. 1.3.5 [Where can I find me some citric acid?] From Jeff Benjamin , rec.food.baking: If there's a home brewing shop in your neck of the woods, try there. From Joel Ehrlich , rec.food.baking: King Arthur's Flour. Most places which sell it for baking identify it as "Sour Salt". From several in rec.food.preserving: Safeway. Food Lion. Ask around. 1.3.6 {Where can I find Clear Gel/Jel A?] >From Carol Nelson : Here are some sources for Clear Jel in western Oregon. I have no idea if they will mail order, but it won't hurt to give them a call. Our local Extension offices sell Clear Jel for $2.00/pound for an idea on price. Captain Albert's Good Things/ 254 Commercial/ Salem, Or (503) 364-6511 Friedman's Microwave Store/ 1120 Lancaster Dr NE/ Salem, Or 364-0538 or 1-888-380-4372 Burrow's Country Store/ 635 Wallace Rd NE/ Salem, Or (503) 585-2898 1.3.6 - [How do I make and use homemade pectin? aka pectin 101 ] Putting Food By so lovingly know as PFB in RFP has the answers here. If you are serious about preserving you do owe yourself a copy of PFB. If you can afford only one preserving book this is it. It is also known in rec.food.preserving with good reason as "the Bible of food preserving". ------- "Pectin is highest in lightly underripe fruit, and diminishes as the fruit becomes ripe; overripe fruit, lacking adequate pectin of its own, is responsible for a good deal of runny jams and jelly. ... This natural pectin in the fruit can be activated only by cooking -- but COOKING QUICKLY, both in heating the fruit to help start the juice, and later when juice or pulp is boiled together with the sugar. And TOO-SLOW COOKING or BOILING TOO LONG, can reduce the gelling properties of the pectin, whether natural or not. ... Testing for pectin content. There are several tests, but the simplest one uses ready-to-hand materials. In a cup, stir together 1 teaspoon cooked fruit juice with 1 tablespoon non-methyl alcohol. No extra pectin is needed if the juice forms one big clot that can be picked up with a fork. If the fruit is too low in pectin, it will make several small daubs that do not clump together. DON'T EVER TASTE THE SAMPLES. Homemade Liquid Pectin Liquid pectin is especially helpful in making peach, pear, strawberry, or those other jellies whose fruit is low in pectin. Four to 6 tablespoons of homemade pectin for every 1 cup of prepared juice should give a good gel: but experiment! These pectins can be frozen or canned for future use. To can, ladle hot into hot [ sterile - ED ] jars, leaving 1/2 inch of headroom; process at a simmer, 185F/85C, for 15 minutes. remove from canner, cool upright and naturally. Crab Apple Pectin 2 pounds sliced unpeeled crabapples 3 cups water Simmer, stirring, for 30-40 minutes adding water as needed. Plop into colander lined with one layer of cheesecloth [ or muslim - ED] and set over a bowl; press to force the juices. To clear, heat the collected juice and pour through a stout jelly bag that has been moistened in hot water. The result is the pectin you will can, or freeze, or use right away. Tart Apple Pectin 4 pounds sliced apples with peels and cores. 8 cups water Simmer, little stirring needed, for three (3) minutes. Press apples through a sieve to remove cores, etc. Return liquid to a heavy kettle [ or use a heavy wide mouth pot to enhance reduction ] to cook briskly, [ and quickly ] stirring, until volume is reduced to one-half. Clarify by pouring though a stout jelly bag that has been moistened. Use, can, or freeze as above. ---------- 1.3.7 - [What can I do with all these peels and cores - the waste? ] Make pectin. Use as few seeds as possible and crush none to preclude ingesting alkaloid and cyanide compounds which are present in lima bean, citrus and apples seeds. The pomace from apple crushing / pressing can be used to generate cider vinegar. Compost is a great way to solve the by-product problem. Your garden will benefit enormously in the years to come. Do make sure the compost works fully so that the seeds are digested. Add a sprinkle of powdered lime to each layer in the compost heap to assure strong action. -- Ivan Weiss has some good words: I don't mean to get into an off-topic thread, but it is inconceivable that there would be enough pesticide residue in any fruit peels to withstand a proper composting process. I can tell you this authoritatively from five years of annual inspections by the Washington state Department of Agriculture for certification as an organic grower. I compost anything that will rot (within reason), and the state, which takes a whole lot of core samples, has never found trace #1 of any pesticides on my place. 1.4 GENERAL EQUIPMENT QUESTIONS 1.4.1 [ Don't you need a lot of stuff?] If you cook, you probably already have most of the stuff that you need to can (jar) high-acid foods. Basically, you need canning jars and 2-piece lids (lids and rings), a large kettle or stock pot that you can boil water in, several saucepans, measuring cups and spoons, light tongs (to pick up the lids and rings), ladles, stirring spoons (stainless steel the best), an accurate timer, clean towels, a cake rack, and canning tongs. As you get more involved, other helpful tools are: canning funnel, clip-on candy thermometer, lid lifter (a plastic rod with a magnet at the end of it), boiling waterbath canner, preserving pan, and a pressure canner (not a cooker). 2-piece jars can be found in the grocery, supermarket, and hardware stores, while canners, canning tongs, jar lifters, and canning funnels can be gotten at the local hardware store (or Walmart). Lots of equipment can also be obtained at yard sales, check out the Specific Equipment Question section for more information. What you really need is a desire to can food, and a bit of a perfectionist streak. Carelessness, disorganization, and inattention cause most problems. * * * and a stove that can do the job: From Robb (rd39462@earthlink.net) Let's first say that there are probably as many preferences for gas or electric as there are cooks who truly utilize their equipment. That said, my own personal preference is ALL electric. My current configuration is a glass top cooking surface containing two traditional underglass coils and two quartz-halogen units. Newer glass top units are far more responsive to rapid control changes than their predecessors. The quartz-halogen units are virtually "instant-on/instant-off". All four of my surface units are capable of bringing a stockpot of liquid to a boil more quickly than the average home gas range, discounting the ultra-high BTU output of commercial or semi-commercial units. I also like the glass enclosed surface units because they contribute less heat to the air in the kitchen, keep the bottoms of all cooking vessels as clean as possible, and are infinitely easier to care for than the myriad parts of any gas range, regardless of quality or cost. In short, it's a terrific pleasure to cook and clean up after a meal. I will admit that complete cooldown of the cooktop is somewhat longer than gas, but that factor doesn't bother me. By the time we've eaten our meal, the cooktop is ready for cleaning. Electric ovens are frequently noted for having more accurate temperature control with less fluctuation. Because they are sealed, they also contribute far less heat to the kitchen area than their gas counterparts. One advantage I particularly like is that food of any kind has less of a tendency to dry out than it does in a gas oven. Many professional bakers prefer electric convection ovens for the above features as well as the temperature stability throughout the entire oven. I've read that there are sometimes hot spots in the gas models. While I'm not at all fearful of gas ovens, my preference for performance is decidedly for electric. In conjunction with that, you might also consider the addition of a warming oven (less space than two wall ovens, or could be mounted under your cooktop), which I have found particularly helpful in maintaining some completed dishes while continuing to cook those that require more time. If I had the room, one concession to gas I would certainly make is including a down-draft gas grill. Nothing beats the flavor of flame grilling. 1.4.3 [What's a preserving pan?] A wide heavy-bottomed pan but with relatively shallow sides. No longer recommended. Use a BWB canner for thorough heating. 1.4.4 [My grandmother always reused commercial jars and sealed her jars using paraffin. Should I do this too?] Nothing against your grandmother, but usually you don't want to use "one- trip" commercial jars for canning. Sealing jars with paraffin is also counterindicated, because mold and other spoilers can slip in between the paraffin and the side of the jar. Even a common trick of turning the jar upside down to "sterilize" the top is not advised. [More on this below.] (Use a boiling waterbath for about 5-10 minutes instead.) Food preserving technique "rules" tend to change every few years, due to new knowledge about microbiology and mycology, and due to rigorous testing of food preservation recipes and techniques by many state extension services. Keep up to date! 1.4.5 [Can I invert my jars instead of using that nasty waterbath thing? (Nope).] From: edecker@inforamp.net (Eric Decker) PFB (Putting Food By) says: "and NEVER invert processed jars in the mistaken idea that you're helping the seal - quite the contrary!" Page 264 of PFB, 4th edition debunks (in my opinion) the 1/8" Inversion theory. My comments will be indicated as [ED] "Unsaid in the news release but voiced by staff responding to telephoned queries to the GF Consumer Center in White Plains, New York, the benefits are that the jam/jelly - being still at a temperature to destroy spoiler micro-organisms - will sterilize the underside of the sealing disk, and the little amount of air trapped under the lid. [How filthy are the lids and jars before use? E.D.] A vacuum can form if the jars are hot and the contents are about 165F/ 74C. But it won't be a STRONG vacuum, because any amount of air left in the jar will invite growth of mould eventually - even though the jar is technically sealed. While a vacuum formed for us at PFB using the "inversion" method, the "inversion" vacuum was not so strong as the vacuum seal on the B-W treated jars. This fact is a reminder that the "finishing" Boiling-Water bath was welcomed by scientists in the South, to counteract heat and humidity of storage in the region; and soon it was adopted for dryer and more temperate climates. [I'd vouch for this: I've canned in Seattle, where seals formed easily, and in Tucson and North Carolina, where the seals took their own sweet time in forming. Give me that finishing waterbath every time-- LEB.] At the same time, food scientists determined that 5 minutes in a B-W bath was adequate (instead of a longer time advocated earlier) to strengthen the seal and drive air from the headroom, and sanitize the surfaces where micro-organisms could have lit. Presumably the reason for standing the jars on their heads is to hold the hot contents against the head and the sealing disk to equal the action of the 5 minute B-W Bath. A further help would be to deal with floating fruit as the medium gels; turned back upright, the contents would shake down by themselves. The same results can be got by giving the jars a twirl several times after they're set aside to cool upright after their bath." (Note: in filing and capping the jars, we at PFB must have left the bands a bit loose. After we inverted it, one jar spurted hot, hot jelly over a hand in a mean scald. This indirect hazard can also make "inversion" less than foolproof.) [Since the writers of PFB know how to tighten a band properly, if bands have to be applied that tight, deformation of the gum is almost certain unless the lids were applied without a sterilization process which softens the gum. E.D.] "PFB is not gainsaying General Foods just to be tiresome; we, too, used to advocate the quick "inversion" with almost non-existent headroom - (though never setting the jars upside-down, regarding this practice as harking back too far to old-time ways with preserving) - so we reverse our own recommendations, too. Postscript: extension food scientists whose work we admire have expressed their worries over the "inversion" technique used at high altitudes and they are against it. Post-Postscript: General Foods shows fairness in their news release in saying they will continue to mention B-W Bath method as an alternative on all their printed materials." [Conclusion: I feel it gives a false security to the user of the "inversion" method. Neophytes especially are at risk with this method for they do not have the experience to make valid food judgements. It is far better then, to master the basic proven techniques that work under all circumstances. Safe, reliable canning is more of a procedure than just a recipe - ED] 1.4.6 [The dishwasher sterilizes jars, right? (Nope)] An argument against thinking the dishwasher sterilizes, paraphrased from Sandy Fifer : The water in the dishwasher is only as hot as the hot water setting in your water heater. Most are set at power saver settings, 130F or so, hottest settings are at 145F. Unless you set your water heater to 212F, you're deluding yourself. And from Eric Decker : The typical dishwasher has an accumulation of crud in the bottom that you don't even know is there. Unless the bottom spray device is removed you have not seen the scraps of food which have not yet dissipated to nothingness and passed through the filter. The dishwasher is not a suitable device for preparing canning jars for use unless one adds an active anti-germ agent such as chlorox [bleach]. Develop good habits. The processes for sterilization of jar and lid must be inviolable and independent of the canning process itself. My grandmother didn't have a dishwasher so she scrubbed her bottles in a hot lye solution, rinsed them in soft running water, then plucked each one of them from a pot of simmering water to use immediately. It may seem silly to iterate it but she always put the mouth of the jar to the bottom - the inside was sealed from the outside and kept full of steam. Talk about a simple way to maintain sterility! [Since you have to use your boiling waterbath, I wash, then boil jars, hold them when I need them, then I have a ready 2/3 canner of hot boiling water. --LEB] 1.4.7 [ Can I use unlined copper pots in preserving? ] Sue Harris wrote: I have recently seen some unlined "copper jam pans" for sale, supposedly to be used in making jam. I am wondering if anyone here has had any experience with these - - are they safe? I thought that unlined copper reacted with acidic foods (which fruit jam certainly would be!). Arno Martens replied: I always thought copper MUST be tinned (led, cadmium and antimony free) before it could be used for ANY food, liquid or solid. On Food and Cooking, Harold McGee "In 1753 Sweden outlawed the used of copper ( unlined is meant) cooking pots in its armed service. In the early 19Th century Britain issued health warnings of the health hazards posed by pickles, beer, bakery products and candies that had been prepared in copper vessels. Copper About 1/10 gram of this element is incorporated into the body, with the highest concentrations in the liver and brain. It plays a role in the formation of hemoglobin and of phospholids, an is also involved in bone development and energy production. Organ meats, shellfish, grains, and most other seeds are good sources. Dietary deficiency of copper is rare, and excessive intake can cause damage to the liver, kidney, and brain. For this reason, and because copper metal readily reacts with many foods, the use of unlined copper utensils in not recommended." Eric writes: Consider that canned foods may be eaten by persons on medication. This presents a great potential for unwanted, unknown and possibly very dangerous side effects. Certainly a copper load uptaken by a child from food prepared in an un-lined copper pot would be more toxic than the same amount to an adult. No doubt the symptoms in that child would be never be seen as copper poisoning but would be called colic, stubborn or something else. In the middle aged and older adult the degeneration from accumulation of copper would be seen as aging, the effects of having lived life of consumption or simple dementia. Live long, live well - use utensils which are safe. 1.4.8 - Can I use a propane "Cajun Cooker" style burner for canning? Ross Reid wrote: There are various makes of propane cookers on the market but they basically fall into two types. There is a "ring" style burner and a "jet" style burner. They are available with various Btu/hr ratings, right up to 200,000+ Btu/hr. The "ring" burner style normally falls into the lower end of the range. I have one of each but, the "ring" burner is the one I use almost exclusively. It has an input rating of 68,000 Btu/hr. The average kitchen range surface burner runs from 8,000 to 12,000 Btu/hr so you can see the advantage of the outdoor propane cooker in this respect. Flame control on the "ring" style burner is excellent, from very low for maintaining a nice simmer right up to a very energetic full rolling boil. Ring burners also make far more efficient use of propane and, a big plus, they are very quiet in use. My "jet" burner is rated at 135,000 Btu/hr but, its flame is much harder to control. Trying to maintain a nice gentle simmer is impossible. It is far less efficient with respect to propane use and, if operated anywhere near full output it sounds similar to an F-18 ;-(. If you go shopping for a burner, it is quite easy to tell the two types apart. The "ring" style is just like its name, the burner itself is a ring, (sometimes more like a starfish), about 8 inches in diameter with upwards of 100 small holes. They usually fall in the range of 35,000 to 70,000 Btu/hr ratings. The burner in a "jet" style is only about 3 or 4 inches in diameter and has a cast iron flame diffuser in the centre. This diffuser can best be described as a multi-tiny-pointed star, usually with one screw in the centre to hold it in place. These are the ones that can run up over 200,000 Btu/hr ratings. I purchased my ring-style burner at a home improvement outlet here in town called The Building Box. It was CDN $49.97 complete with regulator and hose. The name plate on the unit lists the manufacturer as: S.R. Potten Limited, 1645-50th Avenue, Lachine, Quebec, Canada H8T 3C8 Phone 1-800-667-7313 Zxcvbob ( not an anonymous name, per se - Bob's particulars is known to this FAQ Maintainer) wrote: In a welding class I took in college, I learned to only crack open the valve on compressed fuel welding tanks, so you can shut off the valve quickly in case of an accident. This would be good advice when working with portable propane tanks for operating these "Cajun Cooker" burners. (Valves on high pressure non-fuel tanks, like oxygen, nitrogen, 3000 psi air, carbon dioxide, are opened all the way becuase the valve has a second seat that seals the packing when the valve is fully opened to prevent a slow leak). Best regards, Bob P.S. Butane has about twice the BTU rating per pound as propane, so if you can buy butane instead of propane for summer use, it is usually a good deal. In cold weather, butane does not have enough vapor pressure to be useful. 1.5.1 [What about zinc rings, rubber sealed jars, and other great, but antique, canning equipment?] A great question. Check out the answer under Specific Equipment Questions. 1.5.2 [Ball or Kerr?] People have used both, and people have had problems with either. In other words, whichever works for you. from Wendy Milner : Canning jars such as those made by Kerr or by Ball, have special two-piece lids. You should only use lids and jars made by the same company. While in most cases you will get a seal when mixing brands, it is not guaranteed. Additionally, if you are using an oil mixture in your recipe do not use Kerr lids as the sealing compound on the lids has been shown to loose its effectiveness as the oil seeps into it. [As of 3/96, the point is moot. Ball bought out both Bernardin and Kerr. Soon the lid gum composition and amounts on the lid will be similar.] [1998 - the Kerr lids and Bernardin are still different in use ] 1.5.3 [Rings on the jar, or off?] Pros and cons of each side: Pro ring: "looks" more natural, secures the lid if you are mailing canning jars or storing leftovers in the refrigerator. I like the ring on when I mail/give something. [ Absolutely - there must be some _insurance_ the lid will not be loosened with the result of untold ruination - ED] Con ring: can reuse ring quickly, rings don't rust on jar, doesn't hide dirty threads or a weak seal. Other ring facts: rings have to be off if the canned good is to be judged at a county/state fair. Rings shouldn't be removed until the seal is allowed to fully develop, about 12-24 hrs. Gamut of opinions: From edecker@inforamp.net (Eric Decker) ... "the best canners will NEVER store food with bands on". It is a point of pride with those canners that their process does not need "nails and glue" to maintain its integrity. Get thee to an Amish or Mennonite food/bake sale... Yes, removing bands is the default condition in serious canning. Heck my grandmother canned a lot of meat and fish. Never did I see a banded jar in her cellar. Take a peek in my cellar: I have bottles of fruit in alcohol that have been there since 1986 without bands. sandy@chinook.halcyon.com (Sandy Fifer) wrote: What's all the hubbub about leaving the bands on after canning? When I'm done canning my jam I remove the bands, wash the jars (sometimes they're sticky from some jam leaking into the canning water), dry them, test the seal by lifting by the lid, and then loosely replace the bands. Once the jar is opened you need the band to seal it anyway, don't you? And don't you give a band with each jar when you're giving the jars away? And when I'm done with the jam I wash the jar and store it with the band. All of you who remove the bands--where do they spend the winter? From: adhdmd@scc-uky.campus.mci.net (Jackee) After our canned goods have sealed we always remove the bands, wash and use again. My father says that was what his grandmother always did, so we just do the same. They did it because they were dirt poor, why we do I am not sure. From: jpnan@prairienet.org (Jean P Nance) I find that removing the screw caps, washing them, and storing them dry pre- vents rust. It seems if I leave them on, they are much more apt to rust and rust interferes with a seal. Rust and corrosion are especially bad in rings on pickles, where some of the acid seems to seep out and collect on the ring. 1.5.4 [What if I don't hear a pop from my jars?] [And is there a way to be sure they are sealed since I didn't hear that magic noise? --Nancy Delly >From George Shirley < >: Nancy: Be sure the center of the lid is depressed, generally that means they are sealed unless some mean person pushed them all down while you weren't looking. I've found that if the lid didn't seal it will usually fall off when you remove the band, but is sealed if the center is depressed. I don't have time to listen to each individual jar. >From Mary Delamater <>: My jars often don't pop, so I just check to see if the lids are concave. It usually happens pretty quickly after water bathing. Also, if I'm not sure, sometimes I will remove the ring and hold the jar by the lid--if it stays on, it's sealed! (Be sure to put your other hand under the jar in case it is not sealed, or you will have a big mess to clean up :-) ) 1.5.5 [I'm really cheap. How can I reuse my canning lids?] Penny-wise and pound-foolish. The botulism antiserum shot costs a *lot* more than the $10-$20 cost of a few dozen lids. As a public service, from the home office in Grand Rapids MI, the top ten Things You Can Do With Old Canning Lids. 10. Windchimes 9. Coasters for the vacation house 8. Really boring mobiles 7. Palm protectors for smashing garlic cloves 6. Train your pet Chihuahua to catch teeny metal frisbees 5. 2 canning lids + 1 HD disk = yummy sandwich for your favorite USENET FAQ maintainer 4. With tin snips, create several dollhouse-sized cookie sheets 3. Sharpen the edges, make the business end of a pizza cutter 2. Glue several canning lids into 1 slinky to contact those pesky Venusians 1. Several hundred canning lids, stitched together make the perfect dress for your Oscar acceptance speech... (those brass ones look great, much better than AMEX cards!) Seriously, there are some things you can do with old canning lids. You might not realize this, but lids and the mouths of jars/cans are of a fairly standard size. The Kerr lids for the narrow neck pints/half pints fit many commercial jars, like spaghetti sauce and mayonnaise jars, even those medium size salsa jars. I've found that the wide mouth ones fit large tomato sauce cans. It means that if you store dried peas, lentils, beans, pasta, sugars, flours, nuts, seeds, your dried vegetables, dried fruit, jerky, dried herbs, fruit leather, etc. in reused commercial glass jars, you always have a lid. Poke many large holes in an old canning lid, use the lid/ring/jar as a jar strainer for bean and alfalfa sprouts. If you're like me, and you cut the can lid off completely but you don't use all the contents, you still always have a lid. If your jars have great seals, and you have to completely des- troy the lid of a particular home-processed can, you've still got a spare lid when you put it in the refrigerator. If your SO has a workshop, and organ- izes screws, nails, loose change, spare RAM chips, matches, etc in glass jars, your SO has a lid. Just don't can with them, and if you save old lids, mark 'em well so you don't get confused. Scratches on the top with a corkscrew do it for me, you even get planned obsolescence that way. And for god sakes, don't pawn 'em off at a yard sale. 1.5.6 [How do I use a pressure canner safely and effectively?] from Wendy Milner : As with the boiling water bath, you prepare your food according to a tested recipe, place the food in the jar, put on the two piece lid, and place the jars in the canner which has 2 to 3 inches of water in it. The water should be hot but not boiling. Place the lid on the canner. The petcock or vent of the lid is open. As the water boils, steam will rise out of the petcock. When steam is steady, wait 10 minutes before closing the petcock. There are two types of gauge: weighted and dial. The weighted gauge has three positions: 5 pounds, 10 pounds and 15 pounds. Always use the higher weight if the recipe calls for a weight in between one of these values. For example, the recipe calls for 12 pounds of pressure, use 15 pounds. With a weighted gauge, place the gauge on the vent using the correct weight. Leave the temperature on high until the weighted gauge begins to rock. Lower the temperature. You will have to experiment a little with the temperature. You want the weighted gauge to rock lightly throughout the processing time. Start the processing time when the gauge is rocking at about 2 to 3 times a minute. [N.B. If your gauge refuses to rock, check to see if your stove is perfectly leveled.-the gang at r.f.p] The dial gauge canner has a dial which registers from zero to 20 pounds. You should have your gauge tested every year by the local extension office. The advantage to a dial gauge is that you can see exactly what the pressure of the canner is during processing. With a dial gauge, close the petcock and watch the dial. When the dial has reached the proper pressure, reduce the temperature. Maintain the pressure throughout the processing time. Start the processing time when the correct pressure has been met. If you live above 1000' feet you must increase the pressure for processing. For every 1000' feet add 1/2 pound of pressure. You do NOT add time to the processing, only pressure. At the end of the processing time, turn off the heat. Do not open the lid or vents. It will take about an hour for the pressure to drop inside the canner. Wait till pressure reaches zero, or the safety valve drops before opening the lid. Open the lid away from you. There will still be steam rising from the water and it is easy to scald yourself. Remove the jars from the canner. Place them on a towel on the counter and leave them alone for 12 to 24 hours before checking the seal. Do not check before the 12 hours as this could cause the jars to not seal. Sealing is the result of heating and then cooling the jars. [For more about pressure canners especially information about the vagaries of the gauges, please checkout the Equipment Section in part 4 of this FAQ.] 1.5.7 [I'd like some sources for non-standard size jars, decorative bottles, unusual size rings, and other items that I just can't find in the usual places.] Zlotka : Berlin Packaging has a great catalog of containers for all manner of things. 1-800-4-BERLIN will get you a free catalog. Good customer service, too. lost the attribution here, sorry.. You might try Glashaus. They have some big jar sizes, the largest rings I have from them are 4.25" at the outside. They are at Glashaus Inc./ Crystal Lake,IL (815) 356-8440. 1.5.8 [ Pump N Seal, Has anyone used these?] Connie TC wrote: "Pump and Seal ( the hand operated vacuum pump, right?) I found that it did seal jars fine but I didn't like putting a hole in lids-they seemed to rust easily. But for plastic bags, while it could draw a vacuum it was hard to get the bag closed before you lost it and the vacuum wasn't as good as one from the Tilia vacuum and bag sealer machine, which I got last year and really like." Jay Heyl wrote: "It does fine on jars, assuming you have a good seal around the rim. I use it all the time for dry goods stored in canning jars. With bags I would recommend going some other way. The Pump-n-Seal pulls enough vacuum, but you need to be an octopus to work the pump, maneuver the hose inside the bag, and then seal the top of the bag. There's also the small problem that Zip-Locks are not vacuum tight." 1.6 TROUBLESHOOTING 1.6.1 [My jars refuse to seal! Some of my preserved food is turning colors! What is happening?] ---- PROBLEMS WITH HOME-CANNED FOODS----------- Even when you follow directions, occasionally you may have problems with home-canned foods. Many of these problems can be traced to use of non-standard canning jars, lids and rings or use of other-than-recommended canning equipment or procedures. Checking your equipment and reviewing current canning recommendations can go a long way towards preventing potential problems. If you do have a problem, you may be able to determine the cause and prevent its reoccurrence by consulting this "trouble-shooter's guide". 1. Jars do not seal a. Off-standard jars and/or lids. b. Chipped or uneven sealing edge. c. Using one-piece caps instead of two-piece lids. d. Screwbands are rusty or bent providing poor contact. e. Bands not screwed down tightly enough before processing. f. Sealing edge not clean. Wipe edge well before placing lid on rim. g. Liquid siphons out of jar during processing taking food particles on to the sealing edge. h. Insufficient heat during processing. Air is not evacuated from jar, so a vacuum seal never forms. [In pressure canning the EXHAUAST phase is critical -ED] i. Lids were improperly prepared before placing them on rims. Most lid manufacturers require some pretreatment (heating, boiling, etc.). [ Use lid strictly according to the manufacturers specifications. There are significant differences between the lids of various manufacturers. -ED] j. Rapid, forced cooling of a pressure canner can cause a rapid pressure and temperature change inside the canner causing the liquid to "boil" out of the jars, leaving particles on the sealing rim and unsealing the jars. Canners should not be "forced" into cooling rapidly by submerging [ no dousing or spraying either - ED] them in water or by adding ice. k. Insufficient processing of raw-packed food; the air may not have been completely driven out of the food leaving residual air in the jar so the seal does not form. l. Use of canning procedures which are not recommended such as open kettle canning, microwave canning, and oven canning. Use USDA recommended procedures. 2. Food spoils a. Processing at an incorrect temperature. Can occur with: 1. Inaccurate pressure canner gauge. 2.Failure to exhaust canner. 3. Failure to make altitude adjustment. 4. Heat source fluctuates--inaccurate pressure or fluctuating pressure. 5. Water not at a rolling boil when jars are put into canner. 6. Water not covering jar caps by 2" throughout processing. 7. Water not at full boil throughout processing. 8. Insufficient processing time. 9. Use of canning procedures which are not recommnended. Recommended procedures (USDA) are based on the time it takes to achieve a temperature which will sterilize the food in the jar. b. Improper cooling of jars after processing. 1. Failure to remove jars from canner when processing time is up (or when pressure gauge reads 0). 2. Failure to set jars at least 1" apart during cooling. 3. Covering jars which retains heat. Vacuum does not develop. 4. Attempting to cool either the canner or the jars very rapidly. c. Using damaged (freeze damaged), spoiled, under ripe or over ripe food. The pH may not be correct for the type of processing you used (water bath versus pressure). d. Very large number of microorganisms due to spoilage, bruising, etc. A very large number of microorganisms present on the food which are not destroyed in the usually recommended amount of processing time. 3. Food loses liquid during processing a. Jars filled too full. b. Fluctuating pressure in a pressure canner. c. Forced cooling of a pressure canner. 4. Food turns dark (not spoiled) a. Insufficient processing time. b. Processing temperature too low (water not at a full boil at beginning of processing or drops below full boil during processing). c. Water not 2" over jar lids. d. Packing foods raw that should be precooked (pears). e. Liquid loss during processing causing fruit at the top to be out of the liquid. f. Lack of appropriate pretreatment for light-colored foods. 5. Fruit or tomatoes float or separate from the liquid a. Using overripe fruit. b. Packing fruit too loosely. c. Syrup too heavy. d. Processing too long. Pectin is damaged. e. Processing at too high a temperature (pressure canner). f. Raw packing. Raw food contains a lot of air. g. Smashing or pureeing food prior to heating it activates enzymes which break down pectin in the juice so the food pieces are lighter and rise to the top. Heat or crush while heating any foods to be pureed or food to be packed in its own juice to help prevent separation. Prepared by Susan Brewer/Foods and Nutrition Specialist/Revised, 1992 EHE-665 ---- PROBLEMS IN HOME-CANNED FRUITS Fruit darkens at the top of the jar: a. Liquid didn't cover the fruit--pigments become oxidized. b. Fruit not processed long enough to destroy enzymes. c. Air left in jars permits oxidation (bubbles or too much headspace). Fresh fruit exposed to air oxidizes. d. Exposure to high temperatures and light during storage. Color changes in canned apples, pears, peaches, quinces: Pink, red, blue or purple color--natural enzymatic reaction (not harm- ful) which may occur during cooking, or a result of a chemical reaction between fruit pigments and metal ions (iron and copper). Use soft water, stainless steel cookware, plastic or wooden utensils. Fruit floats in the jar: a. Fruit is lighter than syrup. Use lighter syrup, cook fruit before packing. b. Improper packing. Pack fruit tightly without crushing. Use hot pack method. c. Fruit is overprocessed. Too much heat destroys pectin and acid, so the fruit loses its shape and floats. d. Fruit is packed too loosely. Fruit Spoilage: a. Overpacking. Heat penetration is poor and food does not become sterilized. b. Poor selection of fruit (over ripe, wrong pH, large bruises). c. Underprocessing. Food is not sterilized. d. Unsanitary conditions. Microorganisms are not removed from the food or larger numbers are added during preparation. Clean up as you go. Wash equipment, utensils and hands in hot soapy water. Prepared by Susan Brewer/Foods and Nutrition Specialist/Revised, 1992 ---- COLOR CHANGES IN HOME-CANNED FOODS The pigments in food which are responsible for their colors are sensitive to a variety of things which they may come into contact with during home food preservation. Acids (lemon or other fruit juices), anti-caking ingredients in table salt, minerals in water, metals in water and from cooking utensils, heat, and light are a few things which can affect these pigments causing them to change color. Most color changes which occur during home food preservation do not make the food unsafe to consume. Hhowever, if the food looks or smells bad or odd, do not take a chance, dispose of it without tasting it. 1. Blue garlic: Occurs in pickled products. Caused by using immature garlic or because table salt was used in place of canning salt. Not a safety hazard. 2. Yellow cauliflower: Cauliflower (or other white vegetable pigments) are white in acid but yellow in alkaline medium. Minerals in the water may have created a more-than-normal alkalinity. Not a safety hazard. 3. Yellow crystals in canned asparagus: the crystals are glucosides (rutin) which were in the asparagus cells before canning. The high temperature of pressure canning causes them to come out of the vegetables into solution, but when the food cools, the pigment precipitates out of solution onto the the asparagus. Occurs mainly in asparagus in glass jars. If asparagus is canned in tin cans, a pigment-tin complex form so the yellow pigment stays in the liquid. Not a safety hazard. 4. Pink pears: the light colored pigments in the pears convert to pink pigments due to overprocessing or due to enzymatic reactions. Not a safety hazard. 5. White crystals on tomato products: home-canned pureed tomato products may have crystals of calcium nitrate on the surface. They are hard and scaly unlike mold spots. Not a safety hazard. 6. White crystals on spinach leaves: calcium oxalate - not a safety hazard. 7. White or pink crystals in grape jelly: Grapes are high in tartaric acid which goes into solution during cooking but precipitates as crystals during cooling. Prevent crystals by extracting grape juice, cooling overnight in the refrigerator and filtering juice before canning or using for jelly-making. Not a safety hazard. 8. White, yellow, or pale red beets: the red pigments in beets (anthocyanins) are sensitive to high temperatures. Some beet varieties are especially sensitive. The pigments are converted to white or colorless derivatives. Not a safety hazard. 9. Blue pickled beets: the pigments in beets are pH-sensitive. They are red in acids and blue in alkalis. If the pigments are blue, the pH is too high for water-bath canning to be safe. Throw the beets away (handle according to spoiled food procedures). 10. Brown green beans: enzymatic color changes occurring before the enzymes are inactivated by heat cause the green-to-brown color change of chlorophyll. Blanching or hot-packing will inactivate the enzymes and help preserve the green color. Not a safety hazard. 11. Brown potatoes: storage of potatoes at temperatures below 45F causes the potato starch to be converted to sugars. During high heat treatment of pressure canning, these sugars form dark brown pigments. Not a safety hazard. 12. Colorless crystals which look like broken glass in canned sea foods. Not harmful. Prepared by Susan Brewer/Foods and Nutrition Specialist/Revised, 1992 EHE-666 1.6.2 [My jams and jellies didn't set. How can I reprocess them?] From: Barb Schaller Here are three ways to rescue syrupy jams or jellies. From General Foods, makers of Sure Jell pectin products and Certo liquid pectin. USING SURE JELL FOR LOWER SUGAR RECIPES: Prepare containers as you normally would have (hot jars and lids). Prepare Pectin Mixture: Slowly stir contents of 1 package Sure Jell for Lower Sugar Recipes (SJ-LSR) into 1-1/2 cups cold water in small saucepan. Bring to a boil over medium heat; continue to boil 2 minutes, stirring con- stantly. Remove from heat. Prepare Trial Batch: 1 cup your jam or jelly, 2 Tbsp. sugar, 1 Tbsp. Pectin Mixture. Measure jam or jelly, sugar, and the Pectin Mix into small (1-qt) saucepan. Bring to a full rolling boil on high heat; continue to boil 30 seconds, stirring constantly. Remove from heat. Skim off any foam with metal spoon. Quickly pour into prepared jar. Cover jar and let stand up to 24 hours to check set of Trial Batch. Store remaining Pectin Mix in fridge. Prepare Remainder of Batch: DO NOT TRY TO REMAKE MORE THAN 8 CUPS OF JAM OR JELLY AT ONE TIME. If Trial Batch sets satisfactorily, follow the recipe above, using the listed amounts of Pectin Mixture and sugar for EACH 1 cup of jam or jelly. (Not going to repeat previous instructions.--BS) For convenience in measuring larger amounts of Pectin Mixture and sugar: 8 Tbsp. = 1/2 cup. 16 Tbsp = 1 cup. (Even I could do that math! :-) "Remember, if your jam or jelly still doesn't set, you can always use it as a glaze or syrup. " USING SURE JELL POWDERED FRUIT PECTIN: Prepare Containers as usual (hot jars and lids). Prepare Pectin Mixture: Slowly stir contents of 1 package SJ and 3/4 cup cold water in small saucepan. Bring to a boil over medium heat; continue to boil 2 minutes, stirring constantly. Remove from heat. Prepare Trial Batch: Same as for SJ-LSR instructions, above. Prepare Remainder of Batch: Same as for SJ-LSR above. (Same comment about glaze, too. :-) USING CERTO Liquid Fruit Pectin: Prepare Containers: Same as usual (hot jars and lids). Prepare Trial Batch: (Pay attention, this is different.....) 1 cup your sorry jam or jelly, 3 Tbsp. sugar, 1-1/2 tsp. fresh lemon juice (I do use fresh), 1-1/2 tsp. Certo. Measure jam or jelly into small saucepan. Bring to full rolling boil on high heat, stirring constantly. Immediately stir in sugar, lemon juice and Certo. Bring to full rolling boil on high heat, stirring constantly. Remove from heat. Skim off foam, blah, blah, blah. Quickly pour into prepared jar, blah, blah, blah. Store opened pouch of Certo in refrigerator. (Blah, blah, blah - follow standard procedure for sealing the jars, and for g'sakes, don't sneeze in the jar.--LEB) Prepare Remainder of Batch: Do not try to make more than 8 cups of jam or jelly at one time. If Trial Batch sets satisfactorily, follow the recipe above, using the listed amounts of sugar, lemon juice, and Certo for EACH 1 cup of jam or jelly. Measure jam or jelly, sugar, lemon juice and Fruit Pectin into large (6 to 8-quart) saucepot. Bring to a full rolling boil on high heat; continue to boil 1 minute, stirring constantly (this is DIFFERENT than trial batch.) Remove from heat, skim foam, ladle into jars, blah, blah, blah. After pre- paring remainder of batch, discard Certo in opened pouch. (Same commentary about glazes and syrup.) For convenience in measuring larger amounts of sugar, lemon juice and Fruit Pectin: 3 tsp. = 1 Tbsp., 8 Tbsp. = 1/2 cup, 16 Tbsp. = 1 cup. There! From "Gifts from the Harvest, Homemade Jams and Jellies, from the makers of SureJell and Certo." A 62-page booklet with beyond-the-basics recipes for sweet spreads. Got it as a freebie at our State Fair one year. 1.6.3 [Anybody have a way to loosen up stiff jelly?] From: kate@rigel.econ.uga.edu (Kate Wrightson) If it's jelly, try to maneuver a biggish glob (ooh, technical term) out of the jar and into a small Pyrex custard cup. Add a tablespoon or so of warm water and microwave it until the jelly begins to melt; stir and add extra water if needed to make a smooth semi-thick liquid. This becomes a glaze for whatever sorts of meats you might cook: chicken, game birds, roasts, turkey breasts.... The obvious combos are peach glaze on pork, cherry on pork, apple on pork (oops, and we don't even eat all that much pork; suffice it to say that pork goes well with any fruit glaze), strawberry or any berry on cornish hens, kiwi on chicken breasts, etc. 2. FREEZING 2.1 GENERAL QUESTIONS 2.1.1 [What do I *really* need to know about freezing?] Freezing is preserving food using low temperatures--generally at temperatures around 0 F/-18 C. Freezing generally inhibits both microbial growth (doesn't generally kill, though) and many protease/enzyme actions in the food itself. You need to decide whether or not to blanch or process food, how to wrap food to prevent freezer burn, what foods freeze well, and what to do when the power goes out. FROZEN FOODS Food is safe from spoilage AS LONG AS IT STAYS FROZEN. Microorganisms can start to grow as soon as food begins to thaw. To keep microbial growth at a minimum, frozen foods should be thawed in the refrigerator. Thawed food may be refrozen IF ICE CRYSTALS ARE STILL PRESENT IN THE FOOD. Refreezing often changes the quality of food (texture, color, flavor). Foodborne illness causing microorganisms may not be killed by freezing, so the safety of the food will be no better than the condition of the food which was frozen. (section taken from Susan Brewer, from cesgopher.ag.uiuc.edu). [Symptoms of food poisoning are discussed in Section IV. Spoilage--LEB] 2.1.1.1 - Tips on how to choose a freezer From Blanche Nonken Get the biggest you can afford and have room for. I've never heard anyone complaining of TOO MUCH freezer space. Before you shop, look through the large appliance section of your sunday paper. You never know what special deals any number of manufacturers might be offering. Mine's a GE, and GE was offering a "12 Month No Interest Charge!" deal. I took a nice, leasurely 12 months to pay for my $400 chest freezer, because there was no interest involved. Stay away from "Self Defrosting." Emptying it once a year or so for defrost is a great way to spend the hottest day of the year, and you never know just what you'll find. Chest freezers are harder to organize, but are more energy efficient. Uprights, just the opposite - great for organizing, but everytime you open it all the cold air goes flooooosh all over the floor. [ Bulk it up with bags of ice { keep the freezer nearly full at all times} to decrease the running cost. The thermal mass of the ice also aids greatly in getting foods frozen quickly. - ED] 2.1.2 [So what foods can be frozen well?] from Wendy Milner Freezing is not for all produce. Freezing will make mush of many soft fruits and vegetables. Depending on what you want to do with these soft fruits and vegetables, freezing may work. For example, you can freeze tomatoes and later use them to make a sauce, but you would not want to try and use the tomatoes whole after thawing. You can freeze apple slices and later make apple sauce or apple pie. Harder vegetables such as green beans and corn do well in the freezer. These vegetables should be blanched first to kill mold spores and yeasts, dried well, and then placed in freezer bags or freezer containers. The vegetables should be cooled before placing in the freezer to prevent the freezer temperature from rising. All meat can be frozen. If you are butchering your own meat, make sure it is clean of hair, feathers, blood shot meat, and any foreign matter. Meat should be cut into small slices such as you find in the grocery store. Do not attempt to freeze large sections of meat, such as a quarter of a beef, unless you have a commercial sized and very cold freezer. Meat should be wrapped in butcher paper to prevent freezer burn. You must thaw meat in the refrigerator. Meat left on the counter to thaw allows for the growth of bacteria which could be harmful. --- Corn freezes well >From Robb Dabbs: My freezer book says 9 minutes of blanching followed by 9 minutes of ice water. Dry corn, package tightly and freeze. Corn to be cut off the cob requires only 4 minutes of blanching. 2.1.3 [What's this blanching stuff, anyway?] Blanching is plunging your item(s) in boiling water for a short amount of time (30 sec to 5 min, check your recipe), cooling the items quickly, then drying off the items. You don't cook the item, but you kill off the surface bugs and you destroy several important enzymes that brown and degrade foods. 2.1.4 [How do I freeze (your item here), and how long can I reasonably expect it to keep?] From Bobbi Zee RECOMMENDED STORAGE TIMES IN MONTHS Months Appetizers : Cheese wafers and straws 2 : Deviled ham puffs 1 Baked Products Cakes : Angel food -- baked 4 : Chocolate -- baked 3 : Chocolate -- batter 2 : Frosted 3 : Fruit -- baked 4 : Plain -- baked 3 : Plain -- batter 2 : Sponge -- baked 4 Cookies : Brownies -- baked 4 Cookies : Brownies -- baked 4 : Chocolate chip -- baked 4 : Filled -- baked 4 : Peanut butter -- baked 6 : Peanut butter -- dough 4 : Refrigerator -- baked 6 : Refrigerator -- dough 6 : Sugar -- baked 6 : Sugar -- dough 6 Pies : Apple -- baked 4 : Apple -- unbaked 4 : Blueberry -- baked 4 : Blueberry -- unbaked 4 : Chocolate chiffon 2 : Lemon chiffon 2 : Mincemeat -- baked 2 : Mincemeat -- unbaked 2 : Mincemeat -- baked 2 : Mincemeat -- unbaked 2 : Pumpkin -- baked 2 : Pumpkin -- unbaked 2 Quick breads : Boston brown -- baked 4 : Nut -- baked 2 : Orange -- baked 4 Yeast breads : Rolls -- baked 4 : Rolls -- dough 1 week : Swedish tea ring 2 Combination Dishes : Bakes beans with tomato sauce 4 : Beef or veal stew 2 : Chicken a la king 4 : Italian rice 2 : Rice Pilaf 4 : Italian rice 2 : Rice Pilaf 4 : Shrimp Creole 4 : Spanish sausage 2 : Tomato sauce and meat balls 2 Combination Dishes - General Directions INGREDIENTS AND COOKING TIME: Use only ingredients of the best quality. Prepare foods in the usual way but shorten the cooking time for most of them. Cook meat and vegetables until barely tender and take from the heat at once. The tissues will soften further during the cooling, freezing, and reheating. If completely cooked before they are frozen, meat and vegetables may be too soft when served. Long cooking also causes unnecessary losses of flavor and aroma. DO NOT INCLUDE POTATOES OR SOME TYPES OF RICE. Potatoes are not satisfactory in combination dishes which are to be frozen. The texture is poor after freezer storage and reheating. It is better to cook and add them when the frozen food is prepared for serving. In certain combination dishes quick-cooking rice and regular rice tend to be mushy when they are reheated after being frozen. Converted rice has been found to retain its shape and texture better. COOL COOKED FOODS QUICKLY. After a food is cooked, cool it quickly to room temperature. Place the cooking pan in a larger pan of ice water or cold running water and stir occasionally. If the food is in a heavy kettle, you can cool it more quickly by transferring it to one of the lighter weights. CLEANLINESS IS VERY IMPORTANT. Since freezing does not kill all microorganisms, strive to keep the number in the food as low as possible during preparation. Use clean utensils and sanitary methods of handling food. Keep the food covered during cooking, and loosely covered during cooling. Package the product as soon as it reaches room temperature and freeze immediately. PACKAGE CAREFULLY. Several types of containers are suitable for combination dishes. However, the longer the product is to be held in freezer storage the more moisture- and vapor-proof the package must be. Cylindrical cartons with slip-on lids and tub-type containers are easy to fill but they may not be air-tight. Rectangular cartons with plastic or plastic laminated foil bags which can be tightly sealed with paper-covered wire closures, rubber bands, or heat are more moisture and vapor-proof. Glass jars designed as containers for freezing, tin cans, or plastic containers with tight-fitting lids afford good protection against moisture loss and are easy to use. Freezer-to-table cookware can be overwrapped with plastic or aluminum foil for a tight seal. Some of the heavier plastic wraps now available are suitable for freezer storage. Those made with polyvinylidene chloride (such as Saran wrap) have been rated as excellent and are suitable for long-term storage. Those made with polyethylene (such as Glad and Handi-Wrap) are suitable for short-term storage. Those made with polyvinyl chloride (such as Reynolds Plastic) are poor choices because they are not moisture and vapor proof. Plastic-coated paper freezer wrap is suitable for solid foods. (Formore details, see Consumer Reports, March, 1983.) For food that is packaged solid be sure to leave space at the top of the container for the contents to expand during freezing. Leave 1/2 inch for a pint container, 1 inch for a quart. FREEZE IMMEDIATELY. Put packaged foods in the home freezing unit without delay. The temperature in the home freezing unit should be 0 F or lower. DO NOT STORE TOO LONG. The shorter the period of freezer storage, the more appetizing these foods will be. (See table of recommended storage times - LEB) While some foods usually do maintain quality longer than is indicated, undesirable changes may take place during freezer storage. Some fats tend to become rancid rather quickly. Separation may occur in sauces and gravies. Onion and black pepper become stronger and salt loses flavor. With all foods there is a gradual loss of flavor, aroma, and natural texture. Be sure to write the date of preparation on every package and make a record of the packages you put in the freezer so you will not leave them there too long. PREPARE FOR SERVING. To reheat frozen cooked food, use the method which will affect its appearance and texture the least. A double boiler is best for combination dishes. A saucepan can be used if the food is partly defrosted and then heated carefully. With either method do not stir food more than necessary. Plastic wraps can be used in microwave reheating only with foods that are low in sugar and fat. High-fat and high-sugar foods can become hot enough to melt the plastic. Use all defrosted and reheated foods at the current meal. Further holding and reheating is not recommended. COOKED MEAT AND VEGETABLES Freezing cooked meat, except in combination dishes where a solid pack can be prepared for freezing, is not recommended. Work carried on in the foods research laboratory of the University of Illinois as well as in other foods laboratories indicates that higher quality is obtained if uncooked rather than cooked poultry and meat are frozen. Carefully controlled experiments have shown that this is true for deep fat and oven fried chicken, braised beef round steaks, ham patties and loaves, and rib and loin pork roasts. In general, poultry and meat roasted or fried have a more attractive appearance and better flavor than that cooked before freezing. Precooked frozen vegetables have been rated as being inferior to freshly cooked and to blanched frozen vegetables. The few exceptions are products that can be solidly packed such as vegetable purees and mashed potatoes. In the latter case freezing is not recommended because it takes almost as long to thaw and reheat mashed potatoes for serving as it would to prepare them fresh. BAKED GOODS - GENERAL DIRECTIONS Among the baked foods that can be frozen successfully are certain appetizers, breads, cakes, and pies. Freezing and freezer storage preserve the freshness of these products and having them at hand for emergencies is a convenience. The recipes included here are those which were found to give good results when they were tested in the University of Illinois laboratory. Probably many other products besides those described can be frozen satisfactorily. PREPARING BAKED FOODS. Use standard recipes and methods for appetizers, breads, cakes and pies and select only ingredients of the best quality. Several of these products can be frozen before they are baked, the following precautions are necessary: For cakes frozen in the batter state, use double-acting baking powder (SAS-phosphate) in order to assure good volume. Package batter and place in freezing unit immediately. For fruit pies frozen before baking, use a little more flour to thicken juice, and do not prick the top crust. Apple slices should be blanched before they are put in a pit, so they will keep their color, texture, and flavor better. Dough for rolls must be wrapped and frozen as soon as the rolls are shaped. DIRECTIONS FOR PACKAGING. Except for cake batter, these products can be satisfactorily wrapped for freezing in moisture- and vapor-proof plastic wrap, heavyweight aluminum foil, or plastic freezer bags. Heat-sealable plastic bags are excellent. Tight seals prevent loss of moisture and flavor during storage. If you use aluminum foil, place product in center of sheet and fold two edges together over it. Roll or fold the seam tight against the product, taking care not to crush the product. Then press the ends of the package together and fold them close to the product. Pressure or cold-storage tape can also be used to seal plastic wrap or aluminum-foil packages. Plastic of waxed cylindrical freezer cartons with slip-on lids or glass freezer jars are suitable for packaging cake batter. The quart size holds enough batter for an 8-inch square cake and six cup cakes or for two 9-inch layers. DO NOT HOLD TOO LONG IN FREEZER. As soon as baked products, batters, and doughs are packaged, place them in the home freezing unit. Do not, however, keep them in the freezer for long periods because quality is lost gradually during storage. The freezer space probably can be used to better advantage. APPETIZERS Questions about the advisability of freezing canap,s or tea sandwiches are frequently asked. Such products can of course be frozen and held in the freezer for about a week but the results are usually only fairly satisfactory. Freshness in appearance and flavor are apt to be lost, moisture content of bread may no longer be evenly distributed, and crackers or toast rounds tend to lose crispness. However, two appetizers which are baked after freezing can be recommended. Similar types among your favorite recipes may give equally good results. ANGEL-FOOD AND SPONGE CAKES Frozen baked angel-food and sponge cakes, when defrosted, are very similar in quality to freshly baked cake. Angel-food cakes seem a little more moist after they have been frozen and thawed. However, both angel-food and sponge cakes are likely to shrink a little in freezer storage. (Angel food ) cake made from frozen and defrosted batter is not as fine-grained as cake baked before it is frozen.) Delicious angel-food cake can be made from frozen egg whites. Often freezing the whites is more practical than freezing the cake. A pint container will hold the right amount of whites for one cake. After defrosting by holding them overnight in the refrigerator or at room temperature for about 5 hours, use them in the same way as fresh egg whites. FRUIT CAKE Fruit cake can be baked and frozen. After freezer storage the thawed cake will be more like a freshly baked cake than if it had been stored at room temperature. PLAIN AND CHOCOLATE CAKES AND FROSTINGS These cakes can be frozen after they are baked or the batter can be frozen. Storing batter has several advantages: it is easier to package, requires less freezer space, and the cake seems more moist, with a flavor more like that of a freshly mixed and baked cake. A frozen baked cake, however, required less time to prepare for serving after it is taken from storage. In addition a baked cake can be frosted before it is frozen and stored. COOKIES Freezing baked cookies and cookie doughs makes it easy to keep a variety on hand at all times. Many types of baked cookies can probably be frozen, as well as refrigerator cookie doughs. The enclosed recipes give good products, or you may use favorite recipes and methods to prepare cookies for the freezer. PIES Frozen pastry, ingredients for pie fillings, and certain frozen pies make excellent products. Apple, blueberry, mincemeat, and pumpkin pies can be baked either before or after they are frozen. A pie baked after it is frozen is more like a freshly prepared and baked pie, and less time is needed to prepare it for freezing. But a pie that is baked and then frozen takes less time to prepare for serving. Another possibility is to freeze the chief ingredients of fillings and pieces of rolled pastry of appropriate size separately. This procedure is more economical of freezer space than freezing unbaked or baked pies and may in some instances be more practical. Cherries and sugar or pumpkin puree can be frozen satisfactorily for use in pies. Chiffon pies are completely prepared before freezing. Only lemon and chocolate pies have been tested but it seems probable that other chiffon pies will freeze equally well. FREEZING PASTRY. Pastry may be frozen separately and used later. One way to package rolled-out pastry is to cut a piece of cardboard of the same size as the pastry and cover it with waxed paper. Two pieces of waxed paper are put between each two pieces of pastry and several can be wrapped together. Use aluminum foil or plastic wrap for packaging or seal in a large plastic bag with as little remaining air space as possible. Pieces of frozen pastry can be removed as needed and allowed to that 10 to 15 minutes before using in the preparation of a pie. QUICK BREADS A few kinds of quick breads have been baked and frozen with satisfactory results. Probably others will freeze equally well. One advantage of freezing quick breads is to have several kinds available at one time without spending many consecutive hours in their preparation. YEAST BREADS Bread and rolls that are frozen and held in freezer storage do not stale at the usual rate. Yeast rolls may be frozen after baking, or the dough may be frozen. The former method of preparation is preferred because it is more convenient and because the quality of the rolls is higher. The volume, texture, and flavor of the baked rolls are maintained for several months of freezer storage. Frozen dough should be thawed and baked within one week after it is frozen. Swedish tea ring, baked before freezing, was rated good after freezer storage. Other baked products made with sweet roll dough will probably be found to be suitable for freezing. Source: Freezing Cooked and Prepared Foods. Frances O. Van Duyne. University of Illinois at Urbana - Champaign, College of Agriculture, Cooperative Extension Service. Circular 835. July, 1984 Typos by Bobbi Zee 1:230/73 MMMMMMM 2.1.5 [Specifics about freezing meats, especially wild game.] Subject: Preserving Frozen Poultry & Other Meats From: pleasure@netcom.com (Tanith Tyrr) Somebody asked a question about "freezer burn"....here's what I do about it. Works admirably for me, and since I hunt and slaughter livestock, I always have a goodly stack of meat of all sorts needing a deft hand with the long term preserving. Poultry, especially delicate items like wild duck or quail, keeps best when frozen either in a solid block of water (best for the small game birds; use milk cartons) or when frozen completely covered with fat or oil. The key here is "no oxygen interaction". If you can afford one (and if you know how to use it properly), a vacuum sealer is also helpful for processing meats you want to freeze. I'm currently shopping models; input is solicited. I freeze larger game birds, specifically wild duck, crocked in rendered duck fat and wrapped tightly in plastic wrap and a ziplock so that no surface is exposed. It works admirably and "freezer burn" just doesn't happen. The outside fat might lose some moisture and texture if exposed to air, but you can simply melt off the fatty layer and discard. You can also used rendered chicken or goose fat for this purpose, depending on what is in your pantry at the moment. I always save jars of rendered poultry fat of all kinds in the freezer, for this and other culinary purposes. Confit, anybody? ;> [Yep, check out the Meat Potting Section in this FAQ.--LEB] I freeze good cuts of beef and lamb in a solid layer of olive oil, as it does not impart that savory and unmistakable "poultry flavor" that rendered duck, goose or chicken fat does. Any good quality, fresh and not rancid vegetable oil will do, but I prefer olive oil for its weight, durability and flavor. Extra virgin is best, but the medium weight stuff you can buy by the bucket load will do. It depends on how much you value that piece of meat you're putting in the freezer. And taste your oil first to make sure it won't impart unpleasant qualities to the meat; oil or fat can go rancid or "off" if you (or the shopkeeper) leave it on the shelf too long. You can even "freezer marinade" by adding seasonings to the oil or fat and heating briefly, then allowing to cool before adding to the meat to be frozen. You can use a fairly thin (1/4") of fat or oil, so long as you are certain that the meat is covered on all sides and no actual meat surface is exposed to air. Personally, I tend to go for a deep crock when it comes to precious items of wild game; I buy rendered duck fat in 5-pound tubs from specialty stores such as D'Artagnan (NY) or The Game Exchange (SF). Gently melt off all the grease before cooking, and you should end up with a nice piece of well preserved meat even after many, many months in your freezer. Don't forget to invest a small amount in an accurate freezer thermometer, if your model doesn't come with one. It's worth it as fluctuations in temperature or too high a temperature can destroy products inside even if they are properly preserved. 2.1.6 [I'm looking for an appliance to vacuum seal food. Any recommendations?] From: Ross Reid Over the years I've tried several so called vacuum sealers and gave up on them. Most had a tiny little fan which couldn't pull as much of a vacuum as I can by using a drinking straw. However, about a year ago I decided to bite the bullet and spend the extra for a Tilia FoodSaver™ and don't regret it for a minute. The Tilia has a true vacuum pump and, IMO is the only one worth considering as a home vacuum sealer. From: Barbara Rogers : I have a Compact Foodsaver and really like it. I only use it to seal lids on glass jars. I don't use the plastic bags. I have never used anything else so can't compare. This one cost about 200 dollars and I have had it several years with no problems. From: pbyrnes@ix.netcom.com (Patricia C. Byrnes): I also use a FoodSaver. I rarely use the bags, but have a whole collection of containers that work with it (including Mason jars). These are easily sealed. If I were freezing something I wanted to last a long time I would use the bags. From: elva@sos.on.ca (Elva Allen) I have a Phillips vacuum sealer and it works just fine. It seals the plastic to make a bag, and none have split on me yet! It was $35 at Zellers in Ontario, CA. Extra plastic for bags is readily available. From: Buddy McIlwain I have owned a Foodsaver made by a company named Tilia for about 6 years. I have been very pleased with it and with Tilia. They have an 800 number which I used once when my machine quit pulling a complete vacuum on the bags. They correctly diagnosed my problem and shipped the parts overnight. The parts consisted of two strips of heavy duty weather stripping that is used to seal the bags. [snip.] My machine seals plastic bags sold by Tilia, but will also vacuum seal mason jars. From: Paul Hinrichs Tilia, Inc. / 568 Howard St. / San Francisco, CA 94105 415-543-9136 / FAX: 415-777-2634 From: Barb Shaller Bags for Bag Sealers: 5305 Parkdale Drive Minneapolis MN 55416-1681 1-800-KAPAK-57 (1-800-527-2557) I do not know if these bags are usable with the Tilia products. Kapak has a boatload of sizes available. 2.1.6.1 Vac sealing flour: Marie Martinek wrote: I put my circle of waxed paper *inside the jar*. So it keeps the powdery stuff from sucking up into the space between the jar and the lid. Which, of course, also keeps it out of the pump parts. Ross Reid wrote: I put a wad of cotton batting (actually a single cotton ball) up inside the recess in the very top of both my jar adapters. The cotton is held there by a very narrow strip of Scotch™ tape. I've never had flour or anything else get past the cotton and the vacuum still works as well as if the cotton wasn't there. Eric Decker wrote: Test jars done to the methods given here fail. The vacuum held for a couple of months but one by one all twelve test jars lost the seal. The seal at process time was solid. A test removal at process time deemed the FoodSaver's vacuum was adequate. Unfortunately a microscopic level of flour must have been present in all instances. There appears to be no way to guarantee flour will not contaminate the lid. The curent reccomendation is: Do not use vacuum sealing in glass jars for flour. Vacuum bagging flour is effective for those who buy flour in large quantities at infrequent cycles and have a need to exclude pests. Sugar and other higher density, more coarse, items should continue to do okay. 2.1.7 [Now that we found out that a seal-a-meal is worth having...where in the world do you find supplies? Diane M. Ferrell ]. Seal-A-Meal Source ..was called at old number circa Feb/99 and was told that they sold the Seal-a-Meal division to the Rival Company. The Rival Co 1001 Golden Dr Clinton, MO 64735-1195 toll free number (660) 885-5564 Many thanks to Russ Allen for investigating and reporting the info - ED] >From Jenny S. Johanssen : Here in Alaska, we can get the seal-a-meal bags and machine both at Sam's wholesales and Costco. Payless Super Drugs also carries them. I think that Costco is on the West coast - California through Arizona at least. 2.1.8 [How would I go about preserving baked goods (cookies, pastries...) from both going bad and breaking up into crumbs? Gloria] >From Joan : When I am shipping things, I either freeze them or pack them very well. For example, with yeast breads, rolls, etc., I generally freeze them and ship them off with express delivery. That obviously works best if it will be delivered within 48 hours. For items like cookies or tender pastries, I generally find an airtight container for them and then pack them very carefully with lots of waxed paper between the individual items. Make sure they're packed snugly but not enough to crush the items when you put on the lid. Cookies travel very well this way, and some cookies also freeze pretty well so you can ship them in that state to help preserve them. 2.1.9 [Mushroom duxelles.] What's the best way to preserve mushrooms? From: Longhair paulhinr@nando.net (Paul Hinrichs) wrote: The local grocery had some portabellos marked down yesterday and I threw a whole slew of them into my smoker along with the leg of lamb I was smoking at about 130 F. After about 4 hours they were completely dried and smoked and tasted delicious even dry. I suppose you could do the same without smoke in a dehydrator or in the oven. From: jpdion@odyssee.net (Jean-Pierre Dion) I agree, but personally I prefer a duxelle. Steps: 1. Chop your mushrooms as small as possible, a robot does a nice job. 2. Saute the mushrooms in oil or butter (to taste) at low to medium heat. The purpose is remove as much water as possible. They'll shrink and get a concentrated mushroom taste. 3. Cool. Pack tight and freeze. Yes, I wrote freeze. A duxelle is the only way you can freeze mushrooms. Use for soups or sauces. Remember, they will taste much more than ordinary mushrooms. From: edecker@inforamp.net (Eric Decker) Larousse Gastronomique '76 says, and I paraphrase: 1. Chop mushrooms coarsely, put in a bag, express as much moisture as possible by applying a twisting motion to the bag. 2. Saute mushrooms in oil and butter with chopped onion, chopped shallots, salt, pepper, nutmeg, moistened with white wine, with chopped parsley added. 3. Stir over a lively flame so that any surplus moisture in the mushrooms is evaporated - to the degree of a thorough cooking. 4. Allow the duxelles to get quite cold - store in a cold place. Freezing is quite a good option for a large amount of Duxelles. One could add a splash, just a splash, of just about any good brandy instead of white wine. Less is more here. Beware of liqueurs, they will caramelize the duxelles' subtle flavours. 2.1.10 [ Is there any way to freeze cheese so it does not become "crumbly?"] >From Annette Bowser: After you take cheese out of the freezer, let it sit at room temperature 24 hours and then put it in the refrigerator to chill. When you cut it or grate it, it will be like the day you bought it. The oils need to mix back in and it is great and it grates great. -- >From Dawn Crowley: I buy already shredded cheese in 5 lb bags. When my family was smaller, we could not use it fast enough. Therefore, I would flash-freeze it and then put it into ziploc bags in the freezer. To flash-freeze, just spread a layer on a cookie sheet and place it in the freezer for a few minutes. It prevents the cheese from defrosting into one giant clump. 3. DEHYDRATION 3.1 [Dehydration 101] This entire section is Copyright 1997, 1998 by Commercial Dryer Systems Inc. Explicit consent for its inclusion in the RFP FAQ has been given to Eric Decker in the role of RFP FAQ Maintainer. No reproduction elsewhere is permitted without permission of CDS. If this FAQ is reproduced in its entirety with no revisons, inclusion of said article conforms with copyright permission given. Please give attribution if you quote from this copyright section of the FAQ. The URL of this firm is included in setion 16 - Internet. On behalf of RFP I express the gratitude of the RFP family to Mr. Dave Stone of Commercial Dryer Systems Inc for the permission to include Dehydration 101 in our FAQ. ---------------------------- begin here ---------------------------------- Dehydration 101: A Basic Look at Dehydration Dehydration 101 (A primer for new Tray Dryer Operators.) Revised: 5/1/97 Regardless of how brilliant the design, or how skilled the fabricators might be, it is the operators of a Tray Dryer that will make it a success, or failure. The following information is offered as a starting point from which you will be able to jump-start your introduction into the fascinating technology of dehydration. Throughout this lesson, every effort has been made to follow the K.I.S.S. principle. The intent is to provide a basic understanding of dehydration, but without the scientific jargon. This paper is broken down into physics of dehydration, recognition of the four phases of dehydration, maximizing production and finally how to trouble shoot the process when your having problems. Dehydration is more an art form, than an exact science. As your personal experience grows, extend your experience, and don’t be afraid to experiment. There will always be more than one way to dry a specific product. Your challenge is to find that special mix of temperature, air velocity, relative humidity, and dwell time that maximizes both production and product quality. HISTORY: In it’s most simplest form, dehydration technology is thousands of years old. Dried meat on sticks and corn dried in the sun are two examples of early man’s ingenuity. After 1900, the need for technology to accelerate dehydration and remove the dependence process became acute. Acceleration of dehydration and the need to remove the dependence on sunny dry weather where the factors that triggered invention of the Natural Draft dehydrator. This design incorporated a fire near the bottom on a hillside. Stacks of wooden trays filled racks. An exhaust vent in the upper porting of the roof allowed the smoke and hot gases escape with the water vapors. As the fire heated the air, it was carried upward providing the critical air flow and low humidity necessary for dehydration. The Natural Draft Dryer is generally accepted as the first commercial dryer and instituted the use of wood frame trays and artificial heat. Unfortunately, most burned down and today there are no known surviving examples. Ten years later, the Natural Draft Dryer gave way to a mix of crude dryers that incorporated small fans. Finally, between 1910 and 1920, Mr. L. N. Miller invented a box like dryer, with artificial heat made with oil, a large fan capable of high air velocity, humidity shutters and bleeder vents. This was the predominant design through the 1940’s and spawned many variations. In the 1960’s a group of scientists at the University of California, Davis, California, developed the now common overhead return Tunnel Dryer. Variations of this design are now in use throughout the USA and overseas. Commercial Dehydrator Systems, Inc. now carries on the tradition of L.N. Miller’s dryers and the technology from UC Davis, which will keep dehydration alive into the next centuries to come. FOUR PHASES OF HOT AIR DEHYDRATION First Phase. (Raising the Core Temperature) In the first phase of raising the core temperature, the product is warmed as fast as possible without case hardening to within 10 to 20 degrees of the process air temperature. In the counterflow configuration the wet fruit is placed in the cool end and is subjected to very wet air that has lost 20 degrees or more by passing through the Tunnel. This wet air transfers heat very fast and as the car moves forward in the dryer, the process air temperature rises and the humidity drops. This accelerates the transition to the second phase. In the Parallel flow configuration the wet car is placed in the hot end and the product is immediately subjected to the high temperatures and low humidity of the high pressure end. Rather than pulling the product when it is dry (counterflow), parallel flow requires that, at in less than two hours, another car must be placed in the hot end to prevent the previous car from case hardening. Thus the wet product drives the dehydration rather than the dry product. As each car is placed in the high pressure end, a charge of wet, cool air, bathes all of the cars behind it for a few minutes. This dehydration and rehydration cycle continues throughout the process. Second Phase (Rapid dehydration). In the second phase moisture content of the product is in near free fall. To maximize production, moisture inside the dryer needs to be controlled. As a general rule of thumb, moisture content of the process air, when drying most products, measured at the high pressure end, should be 17% to 19%. After the air passes through the dryer, measured at the cool end, the relative humidity should be 35% to 50%. Remember each product is different and should be treated as such. Third Phase (Transition). Transition is the critical phase, from the point of view of damaging the product. The high rate of moisture release experienced in the second phase slows down to a crawl. Most of the free water has been driven off. Capillary action at the cell level now provides the majority of the free water being driven off. The evaporative cooling that has kept the core temperature of the product well below the process air temperature, slows as well. Case hardening, cooking and caramelizing are all very possible as the product passes through the transition phase. Fourth Phase (bake out). The final phase is characterized by a slow reduction in the product moisture content. This phase is normally the longest,and depending upon the target moisture content, may include over 1/2 of the dwell time. Caramelization is still a threat in the last phase, as well. DEFINITIONS: (Hopefully Mr. Webster will forgive the following abuses) Batch Drying: Of the three ways to use the Tray Dryer, Batch Drying is simplest, and least commonly used. Batch drying refers to the loading the tray dryer with all of the product laden trays and cars at one time, and drying the lot, without moving the cars within the dyer. While some react well to this procedure, most don’t The loss in the even and consistent dehydration motivates most operators to investigate other protocols. The problem with batch drying is in the uniformity of the environment the product is exposed to. Since the leading edge of the leading car sees a much different environment than that of the trailing edge of the trailing car, significant differences in moisture content will occur with in the product. It is like drying the same product in two different dryers, each dryer set at a different temperature. Bound water: Water found in most products comes in two forms, free water and bound water. For our purposes , bound water is locked up or bound with salt, sugars, or proteins and as such, are not available for use by bacteria or mold spores for propagation. Bound water is not normally a concern in dehydration. See free water. Caramelizing: Normally associated with fruit and vegetables with significant sugar content. Caramelizing is simply the burning of sugars. Caramelizing is normally associated with running the dryer too hot and with too much air velocity. Tearing open a sample and smelling a Camp fire scent is the classic test. For most purposes a caramelized product is ruined, with no way to salvage it for human consumption. Case Hardening: Like caramelizing, case hardening is caused by too much temperature, too much air velocity and too little relative humidity. Symptoms include a virtual halt in dehydration and a tough leather-like outer skin. Increasing the humidity is the key to salvaging the product. The product can normally be salvaged by massive re-hydration. NOTE: I have seen fire hoses used to wet and re-soften the skin in an effort to kick-start dehydration again. Once softened, dehydration begins almost immediately. Cooked: As with Caramelization above; your product has forever been changed into something else. ( Will not re-hydrate back into the original form.) No amount of re-hydration will help. The oils and sugars inside the product have changed and will not keep. The rancidity clock is ticking and refrigerated storage is the only alternative. Cool End: The cool end of the dryer refers to the end that encloses the fresh air inlet, combustion air inlet and the return air gap (in the air deck). Sometimes called the low pressure end, this part of the dryer brings fresh air, mixes in the return air and exhausts the saturated air. The fan bulkhead separates the Cool End from the Hot End. Counterflow: Counterflow refers to the direction of the air flow within the dryer. The fresh (wet) product laden cars enter the dryer through the cool (low pressure) end doors and are stepped forward periodically as cars loaded with dry product are removed from the dry (Hot End) of the tunnel. When dry cars are removed, an entire row moves forward, and new row of wet cars enter the dryer. With each step forward the product sees a new drying environment; always dryer and hotter. Counter flow dehydration is normally associated with a lower process air temperature and higher quality dried products. Drying is accomplished from the inside out, and case hardening is rare. Dehydration: The process of driving free water from products like fruits, vegetables and nuts, at an accelerated rate, without damage to the product. The purpose of dehydration is to stabilize the product at a low moisture content, so it can be stored without refrigeration, remain free of microbial action and can be re-hydrated to nearly the original form, appearance, taste and nutritive value. Drying Personality Just as people are unique, so are the many products that can be dried in a tray or tunnel dryer. A carrot will respond to dehydration in a radically different manor than a prune. This unique personality causes the product to respond to dehydration in a unique manner, unlike any other product. The variables inside the dryer that you have some control over are: temperature, air velocity, relative humidity and dwell time. Constant monitoring and timely reaction to changing conditions in the product and/or in the environment will insure quality dehydration. Hot End: The Hot End or high pressure end begins at the fan wall and extends across the air deck down through the air deck gap and extends back through the first few cars on the ground level. Distinguished by high static pressure and high process air temperatures, the hot end is where the dry product exits from the dryer when drying in the counter flow configuration. Parallel Air Flow: Parallel air flow is a drying system that maximizes production. The wet cars enter the dryer from the hot end. The hot process air passes through the trays in the same direction as the cars are moving inside the Tunnel Dryer. Parallel air flow is used when production requirements out weigh quality concerns. The process air temperatures are high, sometimes nearly 200 degrees (F). The hot air from the fan reaches the fresh product first. To counter the potential for case hardening, another car full of fruit is placed upstream the first car at a specifically timed interval. The cooling action of moisture driven off the upstream car re-hydrates the original car slightly, thus averting case hardening. The timing of the introduction of the upstream car is critical, which means the last car (wet end) comes out of the dryer, whether it is ready or not. This is the cause of the quality issue. Parallel Flow is an adaptation of the original counter-flow methodology. See Counter-flow air flow. Stewing: Just like it sounds, the product is not drying, normally from too much humidity inside the dryer. Add fresh air. The product is salvageable only when “Stewing” is discovered early. See cooking. Tray Loading: The depth of the product on the tray is driven by drying personality and production considerations. To achieve even drying the tray loading must be consistent and uniform. Heavy on one side and light on the other will result in the heavy side not drying, and the light side over drying. Often seen where trays belly in the center. ------------------------------- end here ---------------------------------- 3.1.1 [ How can I do jerky in wet zones? ] [ The response from Vicky Shaw is on jerky. It is specific to the NW of the US. That includes the adjacent southern portions of British Columbia. While it is specific to jerky this information should aid with dehydration in general in areas that have high humidity and or rain. Thank you Vicky - ED ] Here is a cut and paste of info sheet SP 50-819 Revised October 16, 1997 New Venison Jerky Procedure Home-prepared venison jerky was recently identified as the cause of a foodborne illness outbreak in Oregon. The small electric dehydrator that was used hadn't reached a high enough temperature to kill the harmful bacteria E. coil O157:H7 bacteria can grow in the intestines of deer and contaminate meat during handling. To kill these !bacteria, jerky must be heated to 160øF. while it is still moist. Because most home dehydrators aren't designed to reach this temperature, the jerky must be heated in another way to guarantee safety. This can be done by precooking. Precooking in marinade shortens the drying time and makes