The biga is an important part of baking bread. It is a simple mixture of flour, water, and yeast that is mixed together and left to rise overnight. You add this to the bread during the day you are planning on baking the bread.
2 1/2 cups bread flour
1 1/4 warm water
1/4 tsp yeast
Mix together and let rise over night in a covered container. It will rise but and should be sticky the next morning.