Koshitsumai (hard rice)

Koshitsumai (hard rice) is a type of rice used in sake brewing. Its polished white grains generally absorb water poorly, and the steamed rice feels firm to the touch. As a result, it does not dissolve easily in the moromi (fermentation mash). Consequently, using hard rice tends to produce a relatively large amount of sake lees (sake kasu) during brewing. This makes hard rice important in producing sake with particular flavors and aromas. Because of these characteristics, varieties especially suited to sake brewing are often selected as hard rice.