Currently, rice suitable for sake costs more than rice to eat in Japan. The use of a residual-product, rice powder, in this process by small breweries is currently under study by a technical research institute. Large breweries may already use such residuals in making generic sake in large-volume production. In this process, the starch in the rice is changed to alpha type one for easier conversion to sugar by the action of enzymes. The water content in the rice after polishing differs according to the ratio of polishing.
Drier rice absorbs water much more than does wet rice, and it also becomes too soft after steaming.
This increases the difficulty of the next step. In contrast, wet rice absorbs little water and does not become soft after steaming. This also increases the difficulty of the next step. Rice is also easily affected by humidity. Therefore, the steeping process requires a great deal of attention.