What You Need to Know
The wild yeasts (Saccharomyces spp.) metabolized starches into CO₂ and trace ethanol, while lactic acid bacteria (Lactobacillus spp.) converted sugars into lactic acid, lowering the dough pH to 4.5–5.0. This acidic environment strengthened the gluten network, enhanced leavening, and acted as a natural preservative, imparting a characteristic sour flavor and extending shelf life.
The Science
Primary Reaction
Starch fermentation by yeast and lactic acid bacteria producing CO₂ and lactic acid