Sake, like the rice from which it is made, is at the very heart of Japanese culture. It’s an essential part of religious ritual and celebration, offered to the Gods at New Year, used to seal a contract, consecrate a new building and conclude the marriage union. It’s also a very pure drink; the most important ingredient is water.
Technically, sake is not rice “wine” as it’s brewed. Yet it’s not beer either. Saccharisation, using koji aspergillus mould to convert starch to sugar, and fermentation, using sake yeast, occur simultaneously.
First, the rice is stripped of germ and bran. In premium sakes it is highly milled, leaving only the starchy center of the grain. This results in a refined and delicate taste. Daiginjo is made with rice where as little as 35% of the grain is left. Honjozo has as much as 70% left, whilst in between there is Ginjo 60%.
If a sake is also labelled Junmai it has no added alcohol. Sake is not usually aged, it’s ready for drinking after bottling, and should be kept away from light. Once opened, consume (preferably chilled or at room temperature) within a week or so.