What You Need to Know
During mashing, barley amylases hydrolyze starches into maltose and glucose at 60–70 °C. Subsequent inoculation with wild Saccharomyces yeasts and lactic‑acid bacteria converts these sugars to ethanol, CO₂, and lactic acid, lowering the pH to 4.5–5.0. The combined alcoholic and lactic fermentations generate characteristic sourness and modest carbonation.
The Science
Primary Reaction
Starch → maltose/glucose (amylolysis) → ethanol + CO₂ (yeast fermentation) + lactic acid (bacterial fermentation)