Koji
麹
Brewing Process
Definisi
Steamed rice inoculated with Aspergillus oryzae mold, the essential saccharification agent in sake brewing. Koji enzymes convert rice starch into fermentable sugars, making alcohol production possible since yeast cannot directly process starch.
Mendalam
Koji making (seikiku) is considered the most critical step in sake production, traditionally summarized as 'first koji, second moto, third moromi.' The process takes about 48 hours in a temperature-controlled room (koji-muro) where the brewer carefully manages humidity and temperature to guide mold growth. Different koji styles — from lightly spored tsuki-haze to fully covered sou-haze — produce different enzyme profiles, influencing the sake's sweetness, umami, and overall flavor complexity.