29. How can I determine the proportion of flour and water to

Proportion of water and flour in starter and dough, and why I like
100% starters:

A recent poster related difficulty controlling and predicting the
viscosity of starters. One of the responses referred to the usual
professional baker's practice of measuring by weight, not volume.
This is the so-called "baker's percentage" (or "hydration" or
"absorption ratio"), in which the weight of each of the other
ingredients is compared to the weight of flour used. Thus equal
weights of water and flour make a 100% starter, while a typical dough
made with all-purpose flour is a 60% dough, while one made with all
"bread" flour is typically about 70%, since the extra protein can
trap a greater amount of water. Some European bakers use a variation
of this percentage system, called "dough yield".

Anyway, there is are several advantages to using a 100% starter, with
equal weights of flour and water. One is because it makes it easy to
calculate the amount of water and flour (and salt) that must be added
to the starter to make dough batches of different sizes. For example,
I like to make large loaves that weigh 1500 grams. Forty percent of
that is 600 grams of final starter that I will need when I make my
dough. Forty percent of that amount of starter is 240 grams of
intermediate starter. One-quarter of that is 60 grams, so that is the
amount of my "original" starter I begin with per loaf I will make.

Suppose I want to make about 1500g of dough at 65% baker's
percentage: I divide 1500 by 165 (100% flour, 65% water), then
multiply the result by 65 (for the total weight of water) and by 100
(for the total weight of flour) as well as by ) 0.02 (to determine
the weight of salt needed, which is typically 2%). I am going to need
909 grams of flour, and 590 grams of water, as well as 18 grams of
salt.

Now we see one advantage of using a 100% starter: since I have 600 g
of "final" starter, I have 300 g of flour and 300 g of water, and I
can subtract those amounts easily to give me 609g of flour and 290 g
of additional water, a well as 18 of salt. Adding the starter and
these amounts of flour, water, and salt will make my dough. These
easy calculations are essentially the same for any quantity of dough
you want to end up with on any given day.

The other advantage of a 100% starter is that for MOST starter
cultures a 100% starter will become ripe in 8 hours or less after
each substantial refreshment. That is easy to remember and handle--
thicker starters are often slower, although they last longer in
storage.

Finally, the acid load of a 100% culture is moderate when it is ripe,
so it will make a nicely balanced bread (flavor balance) when
appropriately handled.

-Dan