Seihaku (rice polishing)

Seihaku (rice polishing) is the process of removing the bran and outer layers from the surface of brown rice to produce white rice. This step is very important in sake brewing, because the degree to which the rice is polished greatly affects the quality and flavor of the sake. The degree of polishing is expressed as a ratio of the polished portion to the weight of the rice, and is usually given as the rice polishing ratio (seimai buai). The higher the degree of polishing, the more the rice consists of its central portion, and the sake generally tends to have a clean, delicate flavor. Conversely, when the degree of polishing is lower, the sake tends to have a deeper taste and more of the rice's umami.