Description
Ancient Mesopotamian beer was produced by malting barley, steeping, boiling, cooling, and inoculating with a sourdough starter, then fermenting at ambient temperatures for 1–3 days to yield a mildly sour, low‑alcohol beverage.
Technical
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.
Science
Primary Reaction
Starch → maltose → ethanol + CO₂ + lactic acid
Sensory Profile
Aroma ()
maltyyeastysoursweetbreadyearthyfermented grainhoney-likespicy (from wild yeast)