Rice polishing is used to remove the peculiar protein and fat in the grain, so that the processed rice and other grains are closer to pure starch. Basically, the more the grain is polished, the lighter the peculiar smell will be.
Rice polishing rate (combination of fine grinding/polishing rice) measures the degree of polished rice. For example, a polishing rate of 70% means that 70% of the original rice grains are retained and 30% is polished away. When the polishing rate of rice is low (that is, a large amount of rice is polished off), rice grains are easily broken, so more care, effort and time are needed to pay attention to the polishing process of rice. Because there is a large amount of waste and only a small amount of pure starchy rice can be produced in the true sense, it is also often more expensive.
However, this does not mean that grains with a low polishing rate are better than those with a high polishing rate. For sake made with rice, sake with a high starch ratio tastes like grain and has become more popular recently. The glazing ratio of non-glutinous rice determines the classification of sake such as Daiginjo and Ginza, and is one of the factors that determine the taste and aroma of sake.
High polishing ratio (greater than 60%): salty, granular, strong grain flavor, more likely to be used hot; low polishing rate (less than 60): clean and light, more likely to be used cold.