What You Need to Know
Aspergillus oryzae secretes amylases (α-amylase EC 3.2.1.1 and glucoamylase EC 3.2.1.3) to hydrolyze rice starch into glucose, followed by Acetobacter pasteurianus oxidizing ethanol to acetic acid (CH3COOH) via membrane-bound alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH).
Produces a mellow, umami-rich vinegar with subtle sweetness, essential for sushi rice, pickling, and salad dressings in Japanese cuisine.
Key Parameters
Temperature
32°C
28°C - 38°C
Time
2-3 months
3 weeks - 6 months
Equipment
Wooden koji trays (traditionally cedar)Cotton cloth coversEarthenware fermentation vessels
Steps
- 1.
Sushizu (Edo period Tokyo): Provides balanced acidity that doesn't mask raw fish flavors
- 2.
Sunomono (Kyoto): Delicate acidity complements thin-sliced vegetables
The Science
Primary Reaction
Ethanol fermentation