Tsuki-haze (Spot koji penetration)
Tsuki-haze
Japanese: 突き破精（つきはぜ）
A state where koji hyphae have intensively penetrated parts of the rice grain, creating spot-like penetration patterns. The preferred haze pattern for sake koji-making.
Tsuki-haze is the state where koji hyphae have penetrated intensively into specific parts of the rice grain, with white spots appearing in a scattered pattern. Unlike total penetration, the hyphae do not spread throughout but dig in at discrete points.
In sake koji-making, this spot penetration is often considered ideal. It slows the dissolution of rice, gradually supplying sugars in the mash so yeast can continue gentle, prolonged alcoholic fermentation.
If total penetration is the powerful, fast-acting type, spot penetration is the delicate, slow type. The clear, refined flavors of sake are supported by this penetration pattern. A theme that reveals the depth of fermentation science.