Step 1

Stir the yeast into the warm water and let stand until creamy, about 10 minutes.

Step 2

Stir the remaining water into the creamy yeast mixture, and then stir in the flour, 1 cup at a time. If mixing by hand, stir with a wooden spoon for 3 to 
4 minutes. If mixing with a stand mixer, beat with the paddle at the lowest speed for 2 minutes. If mixing with a food processor, mix just until a sticky dough forms.

Step 3

Transfer the biga to a lightly oiled bowl, cover with plastic wrap, and let rise at cool room temperature for 6 to 24 hours, until the starter is triple its original volume but is still wet and sticky. (The bakers I admire most advise 10 to 11 hours for the first rise, but others are very happy with the 24 hours it takes for dough to truly become yesterday’s dough, and if you like sour bread, allow your biga to rest for 24 to 48 hours or even 72 hours.)

Step 4

Cover and refrigerate or freeze the biga until ready to use. (If refrigerating the biga, use within 5 days. If freezing the biga, let it rest at room temperature for about 3 hours until it is bubbly and active again.) When needed, scoop out the desired amount of biga for your recipe and proceed. I strongly recommend weighing the biga rather than measuring it by volume since it expands at room temperature. If measuring by volume, measure chilled biga; if measuring by weight, the biga may be chilled or at room temperature.