Within the Japonica rice category is a special rice for sake brewing. Sake brewing rice is more suitable than table rice because it possesses better properties as follows:
① Large grain size
② Contains shinpaku（心白：The white and opaque part at the center of the rice)
③ Lower levels of lipids and protein
④ High water-absorption rate
⑤ After steaming, it becomes hard on the outside and soft on the inside
The most important property for sake brewing rice is shinpaku because it is mostly made of starch. The structure of shinpaku helps the hypha of the koji mold (another important ingredient) reach the center easily, and therefore, plays a good role in saccharification.