What is the traditional Japanese rice wine called?

Sake - though in Japanese the word means alcohol generally, and the drink is nihonshu, Japanese alcohol. Ordering sake in Japan is closer to ordering a drink than ordering a specific one.

Wine is also the wrong word for it. Wine is fermented from fruit sugar that is already there; sake requires the starch in rice to be converted to sugar first, which is done by a mould, koji, cultivated on steamed rice. The remarkable part is that the conversion and the fermentation happen simultaneously in the same tank - multiple parallel fermentation, which is unique to sake and is what lets it reach around twenty per cent alcohol, higher than any other undistilled drink.

The grading is mostly about polishing. Rice grains are milled to remove the outer layers, whose proteins and fats produce coarse flavours, and the percentage remaining defines the class - daiginjo requires at least half the grain milled away. The industry is also shrinking sharply in Japan as younger drinkers turn to beer and wine, while exports rise, so a good deal of the best sake now leaves the country. UNESCO added the brewing craft to its intangible heritage list in 2024.