The word sake in Japanese can refer to any alcoholic beverage, but in general, it is used in English to mean a specific type of rice alcohol, also known as nihonshu. It is sometimes called rice wine, but in truth, it is not a wine, nor is it exactly a beer, nor a spirit. Sake is a rather unique type of fermented alcohol.
To begin the fermentation process, rice is milled down until mostly only starch remains. At this point, the starch is fermented to turn into sugar, then further fermented so that the sugars transform into alcohol. This is somewhat similar to the production of beer, but unlike beer brewing, the starch breakdown is not caused by enzymes from the malt, but rather from a special mold.
After fermentation, sake is naturally cloudy from bits of particulate left from the grains. Some, such as nigori, is allowed to remain clouded, but the majority is filtered so that it is clear like a spirit. Sake is best enjoyed while fresh, so unlike wine and more like beer, it is rarely aged. Sake is fairly high in alcohol for a fermented drink, ranging from 14% to 16% alcohol — as compared to 8% to 14% for most wines, or 4% to 6% for most beers. When produced, sake usually contains around 20% alcohol, but most producers add water to dilute the drink to a more palatable 15%.
The original history of sake is not known. Some theories trace it back to mainland China nearly 7,000 years ago, while others place it in Japan sometime in the third century CE. By the seventh century, sake development had reached a fairly high point of sophistication, using a number of techniques borrowed from China. Production continued to improve for the next 500 years, with a number of new techniques and simplifications of older techniques being introduced.
During World War II, the sake industry was dealt a rather vicious blow, as rice, necessary for the war effort, became a critical commodity; as a result of this great need, many producers began adding straight alcohol and sugar to their sake, reducing the quality in a process that continues in some varieties to this day. By the 1960s, however, sake was on the rebound, and by the 1990s, it had reached levels of quality unseen in its long history. Today, many breweries have returned to more classic methods of production, and sake is exported in enormous quantities — even while its popularity in Japan diminishes.