Description
Dual-phase microbial fermentation converting rice-legume matrix into gas-retaining edible foam.
Technical
Combination of lactic acid bacteria (Leuconostoc mesenteroides, Lactobacillus fermentum) and wild yeast (Saccharomyces cerevisiae) metabolizing soaked rice (Oryza sativa) and urad dal (Vigna mungo) starches. Key reactions include amylolysis (α-amylase), proteolysis (acid protease), and CO2 production via heterofermentative pathways.
Culinary Significance
Creates naturally leavened batter for steamed idli (pH ~4.3) with honeycomb structure, or thin crispy dosa when cooked on iron. Traditional stone grinding enhances starch gelatinization while preserving endosperm structure.
Science
Primary Reaction
Lactic acid fermentation
Parameters
Temperature
°C to °C range
Below 20°C favors pathogenic Bacillus growth
Time
8-10h
6h (summer) – 14h (winter)
Full sourness develops by 18h but loses leavening power
Equipment