31. How do I get that lofty loaf?

Getting the lofty loaf starts way back with kneading and getting the
correct consistency (percent hydration). This is easier to do when
you weigh rather than volume-measure ingredients. Next, your
fermentation stage (after kneading, before dividing and rounding)
should not be excessively long. Sourdoughs do not have to double in
bulk in fermentation, as much of their flavor and microbiological
vigor is carried from the prefermentation stages-- from the sponge or
leaven you have made from your active starter.

The next most critical determinant of a lofty loaf is shaping. Some
people shape the finished loaf just after they have divided the
dough, which works well for plastic doughs, like high percentage rye
flour doughs. But for elastic and extensible doughs, like well
hydrated, well kneaded wheat doughs, it is better to divide, round
the loaves (pre-shape, pre-stretch the dough structure) and let them
rest about 10 minutes on the bench. Then when you finally shape them
(means just that, not just making a big lump) you will get the
necessary gluten tension to provide the lofty loaf you seek.

If you are in doubt, underproofing is better than overproofing, Of
course perfect proofing is best. But any well shaped, well proofed
loaf should be able to take slashing by a very sharp knife-- 'been
doin' it for years.

-Dan