Tashitsu koji (high-moisture koji)

Tashitsu koji (多湿麹) is a type of koji that feels very soft and strongly moist when held in the hand. Because it contains a lot of moisture, it is sometimes called the "baka-haze" type (バカ破精型), but its enzyme activity is relatively weak. Tashitsu koji tends to form when the steamed rice has become excessively soft, or when moisture does not evaporate sufficiently from the steamed rice during the koji-making process. Under these conditions, the quality of the koji and the flavor of the finished sake may be affected. In sake brewing, controlling the moisture level of the koji is an important factor.