Kuzumai (broken or substandard rice)

Kuzumai (屑米) refers to lower-quality rice among the rice used in sake brewing. Specifically, it is rice in which starch has not accumulated sufficiently and which tends to break easily during the polishing process. Kuzumai includes further subcategories, such as shiina mai (しいな米), meaning rice grains with no kernel inside; shimai (死米), meaning rice with insufficient starch accumulation; and mijuku mai (未熟米), meaning immature rice. These grains have not stored enough of the starch needed to create umami and aroma, and so are considered unsuitable for improving the quality of sake. In sake brewing, choosing good-quality rice is important, and kuzumai is not normally used as a raw material for sake.