The Basic Steps
Techniques and Recipes
Simple Breads from Straight Doughs
Baking with Yeasted Pre-ferments
Bread Machine Baking
Converting Volume to Weight Measurements
Bread Baker's Glossary
Resources for the Bread Baker
Baking Supplies and Ingredients
Best Bread-Baking Websites
Artisan Bakeries to Visit
Adding Flavor and Character with Pre-ferments
Different baking cultures employ different pre-ferments to bake simple breads with great character. To clarify their similarities and differences, here are descriptions of the four most common pre-ferments.
Sponge. A sponge is a wet mixture of flour, water, and packaged yeast that is allowed to stand for a short period of time (as little as one hour) before being mixed into bread dough. Sponges usually contain a relatively large quantity of yeast, making it unnecessary to add yeast to the dough later. By mixing the sponge an hour or so before mixing the bread dough proper, you give the yeast some extra time to ferment, which will add flavor to the bread.
Poolish. A French-style pre-ferment whose name indicates its heritage as a method brought to France by Polish bakers, poolish is also a wet pre-ferment, but it generally contains less yeast than a sponge and is allowed to ferment longer, at least several hours and sometimes overnight.
Pâte fermentèe. This pre-ferment originated as an economical way for bakers to raise bread - they'd save the leftover dough from the day before and use it (and its yeast) to raise the next day's bread. Pâte fermentèe translates as "old dough". Its name is apt, since it immediately has an "aging" effect on newly mixed dough, lending its developed flavor and active yeast to a new batch.
Biga. An Italian pre-ferment with a dry, claylike consistency, a biga contains proportionately less water than a sponge or poolish. The relatively small amount of water causes the yeast to ferment more slowly, and with less acid buildup, than it does in a sponge or poolish, resulting in a particularly fresh-tasting bread similar in flavor profile to breads employing the direct method but with the extended shelf life of pre-fermented bread.
(For a more complete discussion of these types of pre-ferments, see page 131.)