This grindstone can grind rice to any required size. Albumin is a component of the cell wall and is distributed throughout the rice. Other components such as lipids and minerals are primarily concentrated in the outer layers. Therefore, grinding obviously decreases the amount of undesirable lipids and albumin. This process is so delicate that it is impossible to see whether the rice is broken into pieces.
Overnight monitoring is necessary.
Of course, the cost of very fine sake also increases in proportion to the polishing. 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.