Biga is a type of pre-fermentation used in Italian baking. Italian bakers wanted to find a way to reinforce the strength of their dough. They found that through a simple combination of flour, water, yeast and time you could create a stronger, tastier, and healthier dough for their baking. The recipe for biga dough is quite simple but it takes time to perfect the quantities of the ingredients. Too much water would result in a wetter style of dough like poolish, the French cousin of biga. Using too much yeast would eat up more of the flour than desired and would create an imbalance in the dough. For perfect biga dough, you need a composition of 100% bread flour, 60% water and 1% yeast. To put that into simple metrics, the standard recipe is 500 grams of flour, 300 grams of water and 5 grams of yeast.