Description
Millet grains are fermented by lactic acid bacteria to produce a sour porridge or medicinal decoction.
Technical
During fermentation, Lactobacillus plantarum and related species metabolize the starch-derived sugars in millet into lactic acid, which lowers the pH from about 6.5 to 4.5 within 48–72 h at 30–35 °C. The acidification inhibits spoilage microbes while preserving the product. Moisture content around 70–80 % water activity is essential for optimal bacterial growth; lower moisture retards fermentation and higher temperatures (>40 °C) favor thermophilic yeasts that cause spoilage.
Science
Primary Reaction
C6H12O6 → 2 CH3CH(OH)COOH (lactic acid)
Sensory Profile
Aroma ()
sourearthywarmfermentednuttyyeasty
Origin & History
Civilization
Han dynasty people