The Japan Saké Brewers Association officially classifies saké by the degree to which each individual grain of rice is polished before the brewing process begins. The greater the degree of polishing, the higher the grade of saké.
Daiginjo—the highest classification, at least 50 percent of the rice kernel is removed. Some brewers remove up to 70 percent, resulting in rice grains that resemble tiny pearls. Daiginjo sakés are usually dry, delicate and subtle in their aromas and flavors.
Ginjo—at least 40 percent of the rice kernel is removed. These sakés often taste similar to daiginjo sakés. In Japan, only 2.9 percent of saké sold is daiginjo or ginjo. These styles are also relatively new, having only been brewed and perfected as styles in the early 1900s, somewhat before W.W II, with production increasing in the 1960s.
Junmai—at least 30 percent of the rice kernel is removed. Usually rich in aroma and flavor and full-bodied. They comprise 7.1 percent of all saké sales. Junmai also means “pure rice saké”—saké in which no distilled alcohol has been added to the main fermentation vessel. There are also the sub-categories junmai daiginjo and junmai gingo sakés.
Honjozo—this is also saké in which at least 30 percent of the rice kernel is removed, but some distilled alcohol has been added. Brewers add distilled alcohol to adjust the aromas and flavors of their sakés—not to increase the strength. Rarely sold in the U.S.
Futsu-shu—the most widely sold sakés in Japan (72.4 percent of sales) are those in which less than 30 percent of the rice kernel is removed. These aren’t exported to the U.S.
Specialty sakés include: nama (unpasteurized or draft); nigori (unfiltered, possibly with bits of rice “lees” in the bottle); genshu (“cask strength” or undiluted saké of 18-21 percent); koshu (saké aged over a year); hizoshu (saké aged over five years); taruzake (saké aged in wood casks); and sparkling saké into which carbon dioxide has been added.
All the above can be daunting for the first-time saké drinker. Pierce said that because the lower-end sakés aren’t imported into the U.S., it’s best to think of saké as coming in four categories: junmai, ginjo, daiginjo and specialty.