Sponge Starter

A type of bread dough leavening method that combines some of the benefits of the direct leavening method with the some of the benefits of the sourdough starter leavening method. Less time is required when using the sponge method than with the sourdough method, and although the sponge method provides hints of the depth of flavor and texture that result from the sourdough method, these characteristics are not as pronounced as they are when using the sourdough method. Yeast is used with the sponge method, but the quantity is usually much less than when preparing bread with the direct method. Two of the most widely used sponge starters are the French "poolish" and the Italian "biga."

A poolish is a sponge starter has the consistency of a thick liquid and is very easy to prepare. It requires only a few hours of fermentation before it can be used, but it produces some excellent qualities, such as depth of flavor and a pleasing aroma usually in found breads prepared with the more time consuming sourdough method. The recipe for a poolish starter will differ depending on the type of bread being prepared, but often the only difference is in the quantities of the ingredients that are used in the starter in relation to the quantities of the ingredients in the full recipe. This does not apply to the yeast, which does not change proportionally as the quantities of the other ingredients are changed.

A biga starter is an Italian version of the sponge leavening method or French poolish. It differs from a poolish in that it is firm and dough-like instead of batter-like and it requires a longer fermentation period. Breads made with a biga starter feature a subtle flavor, a porous texture, moist, open crumb, and a champagne aroma. Like other starters, there are several methods for preparing a biga starter, but the biga recipe will differ with each type of bread being made. Often the same recipe for the biga sponge starter can be used for a number of breads if the quantities of the ingredients in the biga starter are changed proportionally to the quantities of the ingredients in the full recipe; however, the quantity of yeast usually does not change proportionally.