Amazake Yodan (amazake fourth-stage method)

Amazake yodan (literally "amazake fourth stage") is a method used in making amazake, in which the preparation uses rice koji, steamed rice, and hot water. In this method, the enzymes in the rice koji first act at a temperature of around 55°C, promoting saccharification, the process by which rice starch is converted into sugar. The sweet liquid obtained through this saccharification is then added to a large fermentation vessel called an oyaoke (parent tub). The result is a richer, more flavorful amazake. This technique is widely used as an important means of adjusting the flavor and sweetness of amazake.