What You Need to Know
The process began with enzymatic hydrolysis of barley starch into fermentable sugars, primarily maltose. Wild yeast in the sourdough starter then reduced these sugars to ethanol and CO₂, while lactic acid bacteria converted residual sugars into lactic acid, imparting a characteristic sourness. The combined metabolic pathways produced a beverage with 2–4 % ethanol, CO₂, and lactic acid, all within a short fermentation window.
The Science
Primary Reaction
Starch → maltose → ethanol + CO₂ + lactic acid