What You Need to Know
Involves staggered additions of rice, koji (Aspergillus oryzae-inoculated rice), and water to maintain optimal yeast activity while preventing osmotic shock. Koji enzymes (α-amylase, glucoamylase) hydrolyze starch into fermentable sugars while Saccharomyces cerevisiae converts them to ethanol.
The foundational process for sake quality, determining alcohol content (18-20%), umami development, and aromatic complexity.
Key Parameters
Temperature
15°C
10°C - 22°C
Time
21-25 days
18 days - 32 days
Equipment
Steps
- 1.
Junmai Daiginjo (Hyogo Prefecture): Ultra-slow fermentation at 10°C for 30+ days maximizes ester formation
- 2.
Kimoto-style sake (Kyoto): Natural lactic acid development creates robust umami
The Science
Primary Reaction
Parallel saccharification (C6H10O5)n + nH2O → nC6H12O6 and fermentation C6H12O6 → 2C2H5OH + 2CO2