Sake (pronounced sah-kay, not sah-key) is a type of alcoholic beverage based on rice that is native to Japan. While sake is incredibly simple to make -- there are only three ingredients (rice, water, and koji, a mold), different variations of rice and water and specialized production methods account for wildly different styles of sake.
True sake was probably first produced somewhere around 600 C.E. For hundreds of years, the government held a monopoly on the production of sake, which was used for religious purposes, and not consumed regularly. After this period, the brewing of sake passed to monasteries, where it remained for nearly another five hundred years. During this time, the methods of producing sake were refined, pasteurization was introduced, and when distillation methods arrived in Japan in the 16th century, brewers took sake and distilled it, making shochu.
After the Meiji Restoration in 1868, the government loosened restrictions in regards to brewing sake, effectively allowing anyone to make it. Very shortly, there were 30,000 breweries in Japan, and by the turn of the 20th century, sake production brought in almost half of all tax revenue in Japan.
The 20th century brought massive amounts of change to the sake-brewing world. Schools were started to isolate proper yeast strains, stainless steel tanks replaced the traditional wooden barrels, and homebrewing was banned. During World War II, with rice crops short, additives such as glucose and alcohol were introduced to sake production. Quality suffered, and has only recently begun to rebound.
The production of sake is fairly simple. Rice is polished to remove impurities, steamed, and inoculated with koji (Aspergillus Oryzae, a type of mold that converts rice starch into fermentable sugars). This is used to make a starter culture, which has more steamed rice and water added to it over a period of three days. Fermentation then takes place, which is usually complete in two to six weeks (with higher quality sake producers cooling the fermentation to prolong it).
The important thing to remember here is that both the conversion of starch to sugar (by koji) and the conversion of sugar to alcohol (by yeast) happen at the same time, so that the process is multiply parallel, and quite complex. After fermentation, the sake is pressed and filtered, Some types of sake allow the addition of pure alcohol before pressing to help liberate aromas and flavors that might be left behind in the lees. After this, most sake is pasteurized, then allowed to rest for a few months to round out aromas and flavors, and diluted with water to bottling proof.
Due to the simplicty of ingredients, a lot of attention is paid to small details like the percentage of rice polished away (called Seimai-buai) Lower percentages have more congeners, but are more fruity, while higher polishing percentages lead to a more "ricey" tasting sake.
Sake can be broken into two major families, of which we'll be dealing with only one: Table sake (Futsu-shu), and Special-designation sake (Tokutei meisho-shu). While table sake is the largest volume produced, most of it does not get imported into the United States. Special-designation sake is further broken down into categories by production method (roughly in order of quality):
- Honjozo -- No minimum polishing requirements. Milling rate must be on label. Alcohol can be added.
- Ginjo -- Must be below 60% (i.e. 40% polished away). Less than 6% of all sake is Ginjo quality. Alcohol can be added.
- Daiginjo -- Must be below 50%.
Other terms you might find on a bottle of sake include Junmai, which means "pure rice", i.e. no alcohol can be added to the sake, Tokubetsu, which denotes a sake made by a specialized brewing process, Nigori, which denotes a sake that is lightly filtered and therefore cloudy, or with lots of sediment, which should be shaken back into the sake before drinking, and Namazake, which is unpasteurized sake.
One recent innovation in the world of sake is the Nihonshu-do, or the Sake Meter Value, which compared the specific gravity of a sake to water. The range of the SMV is between -20 and +20, with +3 being the midpoint. Sake with a SMV value higher than three will be dry sake, while negative numbers are sweeter.
While there are some sake that can be served warm, sake should never be boiled. Most high quality sake is best served in small cups designed for sake, and chilled slightly before serving.