Sponge is a preferment that typically comprises 100% of the yeast and hydration in the recipe. The sponge is the fastest of all preferment, requiring no prep and only takes about one to two hours of fermentation time.
Due to their short fermentation time, sponges are often utilized by enriched bread and flavor-rich recipes where particularly strong preferment flavor or more structure is not required such as in chewer dough such as bagels/bialys, cinnamon buns, as well as babka, challahs, pizza, and pancakes.
Additionally, since sponge fermentation lasts less than 2 hours at around room temperature, a sponge can incorporate ingredients that other preferment cannot such as milk. According to the USDA, milk should not be left out at room temperature for more than two hours which is perfect for a sponge.
