The process where yeast and bacteria convert sugars in your dough into carbon dioxide, alcohol, and organic acids -- it's what makes bread rise and taste good.
Fermentation is the heart of sourdough baking. Yeast produce CO2 (leavening) and ethanol. Bacteria produce lactic acid (mild tang) and acetic acid (sharp tang). Enzymes break down starches and proteins throughout the process. Temperature, starter amount, and flour type all affect fermentation speed. The goal is to ferment long enough for flavor and texture development but not so long that the gluten network breaks down completely.
