Description
Unique fermentation process where starch conversion and alcohol production occur simultaneously.
Technical
Koji mold (Aspergillus oryzae) secretes amylases for starch breakdown while Saccharomyces yeasts concurrently ferment sugars into alcohol. This differs from beer brewing's sequential steps.
Culinary Significance
Enables higher alcohol content (18-20%) than typical yeast tolerance, creating sake's signature umami-rich profile.
Science
Primary Reaction
C6H10O5 (starch) + H2O → C6H12O6 (glucose) → 2C2H5OH + 2CO2
Parameters
Temperature
18°C optimal
15°C to 20°C range
Temperature range for optimal fermentation
Time
18 days
14 days – 21 days
Equipment
Fermentation tankCooling systemStirring mechanism