The S.M.V. (Sake Meter Value) measures the density of sake relative to water, and this is the barometer for gauging the dryness or sweetness of the sake. The higher the S.M.V., the drier the sake The median value of S.M.V. is +3. However, even different brands with the same S.M.V may be perceived as being drier or sweeter.
Often times one might think that the S.M.V. has a great deal of variance from sake to sake tasted, when, in fact, it does not. The variation may be due to the variations in the sugar or level of acidity. The S.M.V. is only intended as a reference number to give you a rough idea of how dry or sweet the sake is likely to be.

Japanese sake is made with rice that has been polished or milled down. The rice polishing ratio is the percentage of the rice that remains after the husk (outer portion) of the brown rice (all rice is brown prior to removal of the husk) is polished off.

The National Tax Administration Agency has developed several categories for different sake's distinguished by their own individual characteristics. This categorizing of sakÿs began in 1989. The different categories were developed for two reasons: there are many great varieties of sake in Japan, and sake brewing techniques have continued to develop over the years.