There are a variety of sake, but it can be roughly divided into two types based on the proportion of brewed alcohol used.
Type 1: 純米酒 Junmai-Sake
Junmai-sake is sake made only from water, rice and Seishu (“clear sake”). Since Junmai is made from simple ingredients, you can fully taste the umami flavor of rice.
Type 2: 本醸造酒 Honjo-Zoshu
Honjuo-Zoshu is sake that uses brewed alcohol in addition to the raw materials for Junmai-Shu (Pure Rice Sake): water, rice, and Seishu (“clear sake”). Brewed alcohol has a higher percentage of alcohol and it is fermented mainly from sugar cane. The rice polishing ratio of white rice and the amount of brewed alcohol that can be used are stipulated in detail. Since it is tasteless and scentless, it offers you more smooth and refreshing flavor.
What is Seishu?
Seishu is one of the genres of Japanese sake.
According to the "Sake Tax Law" revised in 1953, Seishu is defined as "sake that uses rice as a raw material, it always involves a “rubbing process,” and has an alcohol content must be less than 22%." Therefore, sake varieties such as “Doburoku'' that does not include a rubbing process and “Cooking Sake” that has additional raw materials are not considered as Seishu. Additionally, according to the Ministry of National Tax, the official label of “Japanese sake” is defined as “ sake produced in Japan only using the domestically produced rice as a main raw ingredient.”
What is Rice Polishing Ratio?
The “rice polishing ratio” is the percent of which the raw material such as proteins, lipids, vitamins and minerals from the outer part of the rice grain is scraped. The more you scrape it, the less unpleasant the flavor will be. For example, if the rice polishing rate is labeled as 60%, 40% is removed and the remaining 60% is used as the raw material in making the sake. The lower the percentage, the more of the outer skin of the rice has been removed. The lower it is, the more fragrant and refined the sake will taste.
More You Polish, The Better the Sake
Starch is all that is needed to make sake. This is concentrated in the central part of the rice. The surface of the rice that surrounds it is full of important nutrients such as proteins and lipids. However, in sake brewing, if these nutrients take up too much of the sake ration, the unpleasant flavor will remain and the aroma of sake will be diminished. This is the reason why the polishing of the rice directly correlates to the deliciousness of sake.
Hope this was helpful in understanding about Japanese sake a little bit better! Cheers!