Bamforth (2005) places the probable origin of true sake (which is made from rice, water, and Koji (麹, Aspergillus oryzae)) in the Nara period (710–794).
[16][17][18] A large tub with a capacity of 10 koku (1,800 liters) was invented at the end of the Muromachi period, making it possible to mass-produce sake more efficiently than before.
By the Genroku era (1688–1704) of the Edo period (1603–1867), a brewing method called hashira jōchū (柱焼酎) was developed in which a small amount of distilled alcohol (shōchū) was added to the mash to make it more aromatic and lighter in taste, while at the same preventing deterioration in quality.
In the Genroku era, when the culture of the chōnin class, the common people, prospered, the consumption of sake increased rapidly, and large quantities of taruzake (樽酒) were shipped to Edo.
Many of today's major sake producers, including Hakutsuru, Ōzeki, Nihonsakari, Kikumasamune, Kenbishi and Sawanotsuru, are breweries in Nada-Gogō.
[22] During this period, frequent natural disasters and bad weather caused rice shortages, and the Tokugawa shogunate issued sake brewing restrictions 61 times.
As early as the late 17th century, it had been discovered that small amounts of distilled alcohol could be added to sake before pressing to extract aromas and flavors from the rice solids.
During the war, large amounts of distilled alcohol and glucose were added to small quantities of rice mash, increasing the yield by as much as four times.
Incidentally, as of 2022, so much distilled alcohol is not allowed to be added, and under the provisions of the Liquor Tax Act, 50% of the weight of rice is the upper limit for the most inexpensive sake classified as futsū-shu.
[45] The oldest sake brewing company still in operation, as confirmed by historical documents, is the Sudo Honke in Kasama, Ibaraki, founded in 1141 during the Heian Period (794–1185).
[47] In terms of excavated archaeological evidence, the oldest known sake brewery is from the 15th century near an area that was owned by Tenryū-ji, in Ukyō-ku, Kyoto.
[56] In Japan, A. oryzae is used to make various fermented foods, including miso (a paste made from soybeans) and shoyu (soy sauce).
[57] Under warm and moist conditions, the A. oryzae spores germinate and release amylases (enzymes that convert the rice starches into maltose and glucose).
[57] As A. oryzae is a microorganism used to manufacture food, its safety profile concerning humans and the environment in sake brewing and other food-making processes must be considered.
[56] When assessing its safety, it is important to note that A. oryzae lacks the ability to produce toxins, unlike the closely related Aspergillus flavus.
Kimoto and yamahai do not add artificial lactic acid, which allows them to be labeled "additive-free," giving them a marketing advantage when exporting.
The yeasts evolved uniquely in each brewery as they competed for survival by mixing with microorganisms that became airborne and attached to the human body during the sake brewing process.
[65] The second step (the third day of the process), called nakazoe, involves the addition of a second batch of kōji, steamed rice, and water to the mixture.
[65] Here, the third and final batch of kōji, steamed rice, and water is added to the mixture, followed by up to ten days or so of additional fermentation to complete the three-step process.
[65] The multiple parallel fermentation process of sake brewing, where starch is converted into glucose followed by immediate conversion into alcohol,[66] is unique to it.
During the summer and fall, most tōji work elsewhere, commonly on farms, only periodically returning to the brewery to supervise storage conditions or bottling operations.
[73] Tokutei meishō-shu refers to premium sake distinguished by the degree to which the rice has been polished and the added percentage of brewer's alcohol or the absence of such additives.
[32] Sake made in ginjō-zukuri is characterized by fruity flavors like apples, bananas, melons, grapes, peaches, pineapples, citrus, etc.
[40][41][42] The certification requirements for special-designation sake must meet the conditions listed below, as well as the superior aroma and color specified by the National Tax Agency.
[97] In addition to apples and bananas, other fruits mentioned as flavor notes for fruity sake, especially ginjō-shu, include melons, grapes, peaches, pineapples, citrus, etc.
Saucer-like cups called sakazuki are also used, most commonly at weddings and other ceremonial occasions, such as the start of the year or the beginning of a kaiseki meal.
[100] Because the cooler temperatures make it more difficult for bacteria to grow, sake brewing traditionally took place mainly in winter, and this was especially true from 1673 during the Edo period until the early 20th century during the Showa era.
Generally, it is best to keep sake refrigerated in a cool or dark room, as prolonged exposure to heat or direct light will lead to spoilage.
[104] Sake can be stored for a long time due to its high alcohol content and has no use-by dates written on the bottle or label.
[111] These best before dates are shortened when stored at high temperatures or in bright places, especially under sunlight or fluorescent lights that emit ultraviolet rays.