Q: Your column on Jan. 2 discussed preparing bread by the sponge method. You said, "Mix all the liquids, some of the yeast . . ." Using a sponge method, how much yeast would that "some" be? When and how should the remainder of the yeast be added? Also, what causes coarseness of bread's crumb?
A: Most bread recipes work on the straight-dough method. That is, one places the dry ingredients in the bowl, starts the yeast in a little lukewarm water, adds it to the dough when it foams, then adds the remaining liquid while the mixer is turning.
The point of my Jan. 2 column was that you can take any bread formula and change its procedure to the sponge method. The advantage of preparing bread by the sponge method is a moister crumb due to a lower pH (the dough is more acidic), and the bread stales and molds more slowly and has better flavor.
To prepare any bread recipe by the sponge method, place half the recipe's flour (if the recipe contains only half white flour, use all the white flour for the sponge) in the mixing bowl together with all but 1/2 cup of the recipe's liquid. Do not add any of the recipe's sweeteners: that is, add no honey, corn syrup or molasses. Mix half of the recipe's yeast with the liquid (preferably lukewarm) and then stir in the flour.
The sponge, then, comprises only three ingredients: flour, liquid and yeast. The sponge should have a batter-like consistency. Cover the bowl with a plate or with plastic film and allow the sponge to rise in a cool spot -- between 50 and 70 degrees. Five to eight hours should be sufficient. If proofed fewer than five hours, the sponge lacks flavor. If proofed more than eight hours, the pH drops too far as bacteria begin to overpower the yeast and feed off its dying population.
After the 5 to 8 hour proof, the sponge will have risen and fallen several times. At this point, start the remaining half of the yeast in the 1/2 cup of saved liquid (which should be lukewarm and contain a pinch of sugar). When it foams, add it to the sponge as well as all other ingredients save the flour. Then begin mixing in the remaining flour. When it forms a soft dough, turn out of the bowl onto a clean surface (preferably wooden) and knead. The dough should be quite sticky. Do not add more flour at this point. Instead, knead the dough for at least five minutes. If it's still very sticky and soft, knead in some more flour.
Ultimately, the dough should be soft and smooth. After 15 minutes of steady kneading, place it back in the bowl, cover with a plate or plastic film and allow to rise in a 70-degree spot. If the bread dough is rye or whole-wheat, allow it to rise only until 50 percent larger than it was. Then cut and form into loaves or rolls. If it is a white flour dough, allow it to rise to double in volume before portioning and forming.
Coarseness of grain is related to the following:
*Type of flour: the soft wheats -- those lower in protein -- produce breads with holes of more disparate sizes. Pastry flour comes from soft wheats. So does cake flour. There are two reasons why soft wheat flours produce larger holes. One, you shouldn't knead a dough made from soft wheat as long, since it contains less protein, takes less time to develop and then proceeds to disintegrate from overkneading. Shorter kneading time means fewer air bubbles incorporated and therefore a coarser grain. And two, the protein of soft wheats is more extensible. That is, "gives" more during proofing, allowing larger bubbles to grow in size at a faster rate than smaller bubbles.
*Amount of kneading: The longer you knead a dough, the more air bubbles you incorporate into it. The more air bubbles there are, the less each bubble grows to produce X volume of bread. Hence, the bubble size tends to be larger in breads made from briefly kneaded doughs, and smaller in well-kneaded doughs.
*Length of proofing: The longer you proof or allow a dough to rise, the more extensible it becomes. This is related to dough pH: A more acidic dough will expand more readily because of the chemical effects acid has on gluten or wheat protein. An overproofed bread dough usually has a very open texture and the surface of the bread or roll is pockmarked.
*Dough softness: The more water you add to a dough, the more extensible its gluten. Stiff bread doughs produce compact, close-grained breads simply because the carbon dioxide produced by yeast cannot inflate the air bubbles at hand. Instead, the carbon dioxide dissolves in the surrounding dough and forms bubbles that are small to invisible when baked. The dough from which french bread is made (one of french bread's attributes is an open grain) is generally soft.
*Oven humidity: An oven with dry air sets the bread dough early and inhibits last-minute expansion (called oven spring). This expansion can be as much as a 30 percent increase in volume. Without it, the air bubbles in the dough tend to remain small.