Sake is sometimes referred to in English-speaking countries as rice wine. However, unlike wine, in which alcohol is produced by fermenting sugar that is naturally present in grapes and other fruits, sake is produced by means of a brewing process more like that of beer. To make beer or sake, the sugar needed to produce alcohol must first be converted from starch.
The brewing process for sake differs from the process for beer, in that for beer, the conversion from starch to sugar and from sugar to alcohol occurs in two discrete steps. But when sake is brewed, these conversions occur simultaneously. Furthermore, the alcohol content differs between sake, wine, and beer. Wine generally contains 9%–16% ABV, while most beer contains 3%–9%, and undiluted sake contains 18%–20% (although this is often lowered to about 15% by diluting with water prior to bottling).
The origin of sake is unclear. The earliest reference to the use of alcohol in Japan is recorded in the Book of Wei in the Records of the Three Kingdoms. This 3rd century Chinese text speaks of the Japanese drinking and dancing. Bamforth (2005) noted that the probable origin of sake was in the Nara period (710–794 AD).
Sake is mentioned several times in the Kojiki, Japan’s first written history, which was compiled in 712 AD
By the Asuka period, true sake, that which is made from rice, water, and kōji mold (麹, Aspergillus oryzae), was the dominant alcohol and had a very low potency. In the Heian period, sake was used for religious ceremonies, court festivals, and drinking games. Sake production was a government monopoly for a long time, but in the 10th century, temples and shrines began to brew sake, and they became the main centers of production for the next 500 years. TheTamon-in Diary, written by abbots of Tamon-in (temple) from 1478 to 1618, records many details of brewing in the temple. The diary shows that pasteurization and the process of adding ingredients to the main fermentation mash in three stages were established practices by that time.
In the 16th century, the technique of distillation was introduced into the Kyushu district from Ryukyu. The brewing of shochu, called “Imo—sake” started, and was sold at the central market in Kyoto. Powerful daimyo imported various liquors and wine from China.
In the 18th century, Engelbert Kaempfer and Isaac Titsingh published accounts identifying sake as a popular alcoholic beverage in Japan; but Titsingh was the first to try to explain and describe the process of sake brewing. The work of both writers was widely disseminated throughout Europe at the beginning of the 19th century.
During the Meiji Restoration, laws were written that allowed anybody with the money and know-how to construct and operate their own sake breweries. Around 30,000 breweries sprang up around the country within a year. However, as the years went by, the government levied more and more taxes on the sake industry and slowly the number of breweries dwindled to 8,000.
Most of the breweries that grew and survived this period were set up by wealthy landowners. Landowners who grew rice crops would have rice left over at the end of the season and, rather than letting these leftovers go to waste, would ship it to their breweries. The most successful of these family breweries still operate today.
During the 20th century, sake-brewing technology grew by leaps and bounds. The government opened the sake-brewing research institute in 1904, and in 1907 the very first government-run sake tasting/competition was held. Yeast strains specifically selected for their brewing properties were isolated and enamel-coated steel tanks arrived. The government started hailing the use of enamel tanks as easy to clean, lasting forever, and being devoid of bacterial problems. (The government considered wooden barrels to be unhygienic because of the potential bacteria living in the wood.) Although these things are true, the government also wanted more tax money from breweries, as using wooden barrels means that a significant amount of sake is lost to evaporation (somewhere around 3%), which could have otherwise been taxed. This was the end of the wooden-barrel age of sake and the use of wooden barrels in brewing was completely eliminated.
In Japan, sake has long been taxed by the federal government. In 1898, this tax brought in about 55 million yen out of a total of about 120 million yen, about 46% of the government’s total direct tax income.
During the Russo-Japanese War in 1904–1905, the government banned the home brewing of sake. At the time, sake still made up an astonishing 30% of Japan’s tax revenue. Since home-brewed sake is tax-free sake, the logic was that by banning the home brewing of sake, sales would go up, and more tax money would be collected. This was the end of home-brewed sake, and the law remains in effect today even though sake sales now make up only 2% of government income.
When World War II brought rice shortages, the sake-brewing industry was dealt a hefty blow as the government clamped down on the use of rice for brewing. As early as the late 17th century, it had been discovered that small amounts of alcohol could be added to sake before pressing to extract aromas and flavors from the rice solids, but during the war, pure alcohol and glucose were added to small quantities of rice mash, increasing the yield by as much as four times. 75% of today’s sake is made using this technique, left over from the war years. There were even a few breweries producing “sake” that contained no rice at all. Naturally, the quality of sake during this time varied greatly.
After the war, breweries slowly began to recover, and the quality of sake gradually went up. However, new players on the scene—beer, wine, and spirits—became very popular in Japan, and in the 1960s beer consumption surpassed sake for the first time. Sake consumption continued to go down while, in contrast, the quality of sake steadily improved.
Today, sake has become a world beverage with a few breweries springing up in China, Southeast Asia, South America, North America, and Australia. More breweries are also turning to older methods of production.
While the rest of the world may be drinking more sake and the quality of sake has been increasing, sake production in Japan has been declining since the mid-1970s. The number of sake breweries is also declining. While there were 3,229 breweries nationwide in fiscal 1975, the number had fallen to 1,845 in 2007.
October 1 is the official Sake Day (日本酒の日) of Japan.
The rice used for brewing sake is called shuzō kōtekimai (sake rice). The grain is larger, stronger, and contains less protein and lipid than the ordinary rice eaten by the Japanese. The rice has a starch component called shinpaku in the center of the grains. Since sake made from rice containing only starch has a superior taste, the rice is polished to remove the bran. If a grain is small or weak, it will break in the process of polishing. This rice is used only for making sake, because it is unpalatable for eating. There are at least 80 types of sake rice in Japan. Among these, Yamadanishiki, Gohyakumangoku, Miyamanishiki and Omachi rice are very popular.
Water is one of the important ingredients for making sake. It is involved in almost every major process of sake brewing from washing the rice to dilution of the final product before bottling. Mineral content can play a large role in the final product. Iron will bond with an amino acid produced by the koji to produce off flavors and a yellowish color. Manganese, when exposed to ultraviolet light, will also contribute to discoloration. Conversely potassium, magnesium, andphosphoric acid serve as nutrients for yeast during fermentation and are considered desirable. Yeast will use those nutrients to work faster and multiply resulting in more sugar being converted into alcohol. And so hard water, with a higher nutrient content for yeast, is known for producing a drier-style sake, while soft water will typically yield sweeter sake.
The first region known for having great water was the Nada-Gogō in Hyogo Prefecture. A particular water source called “Miyamizu” was found to produce high quality sake and attracted many producers to the region. To this day Hyogo has the most sake brewers of any prefecture.
Typically breweries source their water from wells, though lakes and rivers can be used as well. Also breweries may use tap water and filter and adjust components as they see fit.
Sake is produced by the multiple parallel fermentation of rice. The rice is first polished to remove the protein and oils from the exterior of the rice grains, leaving behind starch. Thorough milling leads to fewer congeners and generally a more desirable product.
Newly polished rice is allowed to “rest” until it has absorbed enough moisture from the air so that it will not crack when immersed in water. After this resting period, the rice is washed clean of the rice powder produced during milling and then steeped in water. The length of time depends on the degree to which the rice was polished, ranging from several hours or even overnight for an ordinary milling to just minutes for highly polished rice.
After soaking, the rice is steamed on a conveyor belt. The degree of cooking must be carefully controlled; overcooked rice will ferment too quickly for flavors to develop well and undercooked rice will only ferment on the outside. The steamed rice is then cooled and divided into portions for different uses.
The microorganism Aspergillus oryzae (a mold) is sprinkled onto the steamed rice and allowed to ferment for 5–7 days (Uno et al., 2009). After this initial fermentation period, water and the yeast culture Saccharomyces cerevisiae are added to the koji (rice and mold mixture) and allowed to incubate at 4 degree Celsius for about 7 days. Over the next four days, pre-incubated mixture of steamed rice (90 kg), fermentated rice (90 kg) and water (440L) are added to the fermented mixture in three series.
This staggered approach allows time for the yeast to keep up with the increased volume. The mixture is now known as the main mash, or moromi (醪, also written 諸味).
The main mash then ferments, at approximately 15-20 degree Celsius for 2–3 weeks. With high-grade sake, fermentation is deliberately slowed by lowering the temperature to 10 °C (50 °F) or less. Unlike malt for beer, rice for sake does not contain the amylase necessary for converting starch to sugar and so it must undergo a process of multiple fermentation. The addition of A. oryzae provides the necessary amylases, glucoamylases, and proteases to hydrolyze the nutrients of the rice to support the growth of the yeast(S.cerevisiae). In sake production these two processes take place at the same time rather than in separate steps, so sake is said to be made by multiple parallel fermentation.
After fermentation, sake is extracted from the solid mixtures through a filtration process. For some types of sake, a small amount of distilled alcohol, called brewer’s alcohol (醸造アルコール), is added before pressing in order to extract flavors and aromas that would otherwise remain behind in the solids. In cheap sake, a large amount of brewer’s alcohol might be added to increase the volume of sake produced. Next, the remaining lees (a fine sediment) are removed, and the sake is carbon filtered and pasteurized. The sake is allowed to rest and mature and then usually diluted with water to lower the alcohol content from around 20% to 15% or so, before finally being bottled.
The process during which the sake grows into a quality product during storage is called maturing.
Mature sake has reached its ideal point of growth. New sake is not liked because of its rough taste, whereas mature sake is mild, smooth and rich. However, if it is too mature, it also develops a rough taste. Nine to twelve months are required for sake to mature.
Aging is caused by physical and chemical factors such as oxygen supply, the broad application of external heat, nitrogen oxides, aldehydes and amino acids, among other unknown factors. It is said that Saussureae radix from the Japan cedar material of a barrel containing maturing sake comes to be valued, so the barrel is considered indispensable.
Tōji (杜氏?) is the job title of the sake brewer. It is a highly respected job in the Japanese society, with tōji being regarded like musicians or painters. The title of tōji was historically passed on from father to son; today new tōji are either veteran brewery workers or are trained at universities. While modern breweries with refrigeration and cooling tanks operate year-round, most old-fashioned sake breweries are seasonal, operating only in the cool winter months. During the summer and fall most tōji work elsewhere, and are commonly found on farms, only periodically returning to the brewery to supervise storage conditions or bottling operations.[unreliable source?]
There are two basic types of sake: Futsū-shu (普通酒?, Ordinary sake) and Tokutei meishō-shu (特定名称酒?, special-designation sake). Futsū-shu is the equivalent of table wine and accounts for the majority of sake produced. Tokutei meishō-shu refers to premium sakes 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. There are eight varieties of special-designation sake.
|Special Designation||Ingredients||Rice Polishing Ratio||Percentage of Kōji rice|
|Junmai Daiginjō-shu (純米大吟醸酒?, Pure rice, Very Special brew)||Rice, Kōji rice||Below 50%||Not less than 15%|
|Daiginjō-shu (大吟醸酒?, Very Special brew)||Rice, Kōji rice, Distilled alcohol[note 1]||Below 50%||Not less than 15%|
|Junmai Ginjō-shu (純米吟醸酒?, Pure rice, Special brew)||Rice, Kōji rice||Below 60%||Not less than 15%|
|Ginjō-shu (吟醸酒?, Special brew)||Rice, Kōji rice, Distilled alcohol[note 1]||Below 60%||Not less than 15%|
|Tokubetsu Junmai-shu (特別純米酒?, Special Pure rice)||Rice, Kōji rice||Below 60% or produced by special brewing method||Not less than 15%|
|Tokubetsu Honjōzō-shu (特別本醸造酒?, Special Genuine brew)||Rice, Kōji rice, Distilled alcohol[note 1]||Below 60% or produced by special brewing method||Not less than 15%|
|Junmai-shu (純米酒?, Pure rice)||Rice, Kōji rice||Below 70%||Not less than 15%|
|Honjōzō-shu (本醸造酒?, Genuine brew)||Rice, Kōji rice, Distilled alcohol[note 1]||Below 70%||Not less than 15%|
]Three ways to make the starter mash
- Kimoto (生酛) is the traditional orthodox method for preparing the starter mash, which includes the laborious process of grinding it into a paste. This method was the standard for 300 years, but it is rare today.
- Yamahai (山廃) is a simplified version of the kimoto method, introduced in the early 1900s. Yamahai skips the step of making a paste out of the starter mash. That step of the kimoto method is known as yama-oroshi, and the full name for yamahai is “yama-oroshi haishi” (山卸廃止), meaning “discontinuation of yama-oroshi.” While the yamahai method was originally developed to speed production time, it is slower than the modern method and is now used only in specialty brews for the earthy flavors it produces.
- Sokujō (速醸), “quick fermentation”, is the modern method of preparing the starter mash. Lactic acid, produced naturally in the two slower traditional methods, is added to the starter to inhibit unwanted bacteria. Sokujō sake tends to have a lighter flavor than kimoto or yamahai.
Different handling after fermentation
- Namazake (生酒) is sake that has not been pasteurized. It requires refrigerated storage and has a shorter shelf-life than pasteurized sake.
- Genshu (原酒) is undiluted sake. Most sake is diluted with water after brewing to lower the alcohol content from 18-20% down to 14-16%, but genshu is not.
- Muroka (無濾過) means unfiltered. It refers to sake that has not been carbon filtered, but which has been pressed and separated from the lees, and thus is clear, not cloudy. Carbon filtration can remove desirable flavors and odors as well as bad ones, thus muroka sake has stronger flavors than filtered varieties.
- Nigorizake (濁り酒) is cloudy sake. The sake is passed through a loose mesh to separate it from the mash. It is not filtered thereafter and there is much rice sediment in the bottle. Before serving, the bottle is shaken to mix the sediment and turn the sake white or cloudy.
- Seishu (清酒), “clear/clean sake”, is the Japanese legal definition of sake and refers to sake in which the solids have been strained out, leaving clear liquid. Thus nigorizake and doburoku(see below) are not seishu and therefore are not actually sake under Japanese law. However, nigorizake can receive the seishu status by being strained clear and having the lees put back in afterward.
- Koshu (古酒) is “aged sake”. Most sake does not age well, but this specially made type can age for decades, turning yellow and acquiring a honeyed flavor.
- Taruzake (樽酒) is sake aged in wooden barrels or bottled in wooden casks. The wood used is Cryptomeria (杉, sugi), which is also inaccurately known as Japanese cedar. Sake casks are often tapped ceremonially for the opening of buildings, businesses, parties, etc. Because the wood imparts a strong flavor, premium sake is rarely used for this type.
- Shiboritate (搾立て), “freshly pressed”, refers to sake that has been shipped without the traditional six-month aging/maturation period. The result is usually a more acidic, “greener” sake.
- Fukurozuri (袋吊り) is a method of separating sake from the lees without external pressure by hanging the mash in bags and allowing the liquid to drip out under its own weight. Sake produced this way is sometimes calledshizukazake (雫酒), meaning “drip sake”.
- Tobingakoi (斗瓶囲い) is sake pressed into 18-liter bottles (“tobin”) with the brewer selecting the best sake of the batch for shipping.
- Amazake (甘酒) is a traditional sweet, low-alcoholic Japanese drink made from fermented rice.
- Doburoku (濁酒) is the classic home-brew style of sake (although home brewing is illegal in Japan). It is created by simply adding kōji mold to steamed rice and water and letting the mixture ferment. The resulting sake is somewhat like a chunkier version of nigorizake.
- Jizake (地酒) is locally brewed sake, the equivalent of microbrewing beer.
- Kuroshu (黒酒) is sake made from unpolished rice (i.e., brown rice), and is more like Chinese rice wine.
- Teiseihaku-shu (低精白酒) is sake with a deliberately high rice-polishing ratio. It is generally held that the lower the rice polishing ratio (the percent weight after polishing), the better the potential of the sake. However, beginning around 2005, teiseihaku-shu has been produced as a specialty sake made with high rice-polishing ratios, usually around 80%, to produce sake with the characteristic flavor of rice itself.
Some other terms commonly used in connection with sake:
- Nihonshu-do (日本酒度), also called the Sake Meter Value, or SMV
SMV = (|1/specific gravity|−1) × 1443
Specific gravity is measured on a scale weighing the same volume of water at 4°C and sake at 15°C. The sweeter the sake, the lower the number. When the SMV was first used, 0 was designated the point between sweet sake and dry sake. Now +3 is considered neutral.
- Seimai-buai (精米歩合) is the rice polishing ratio, the percentage of weight remaining after polishing. Generally, the lower the number, the better the sake’s potential. A lower percentage usually results in a fruitier sake, whereas a higher percentage will taste more like rice.
- Kasu (粕) are pressed sake lees, the solids left after pressing and filtering. These are used for making tsukemono pickles, livestock feed, and shōchū, and as an ingredient in dishes like kasu soup.
Taste and flavor
The label on a bottle of sake gives a rough indication of its taste. Terms found on the label may include nihonshu-do (日本酒度), san-do (酸度), and aminosan-do (アミノ酸度).
Nihonshu-do (日本酒度) indicates the sugar and acid content[contradiction] of the sake. When comparing sake to water, sake that is heavier[clarification needed] than water is listed as a negative value, and sake that is lighter (drier) than water is given a positive value. As examples, “+10” is very dry, and “−10” is very sweet.
Aminosan-do (アミノ酸度) indicates a taste of umami or savoriness. As the proportion of amino acids rises, the sake tastes more savory.
Sake can have many flavor notes, such as apples, bananas, melons, flowers, herbs, spices, rice, chestnuts, chocolates, dry grapes, sherry, caramel sauce, etc. The flavor of apples comes from ethyl caproate, and bananas from isoamyl acetate. These two constituents are contained in many types of sake, such as ginjyoshu (吟醸酒).
In Japan sake is served chilled, at room temperature, or heated, depending on the preference of the drinker, the quality of the sake, and the season. Typically, hot sake is a winter drink, and high-grade sake is not drunk hot, because the flavors and aromas will be lost. This masking of flavor is the reason that low-quality and old sake is often served hot.
Sake is usually drunk from small cups called choko, and poured into the choko from ceramic flasks called tokkuri. Saucer-like cups called sakazuki are also used, most commonly at weddings and other ceremonial occasions. Recently, footed glasses made specifically for premium sake have also come into use.
Another traditional cup is the masu, a box usually made of hinoki or sugi, which was originally used for measuring rice. In some Japanese restaurants, as a show of generosity, the server may put a glass inside the masu or put the masu on a saucer and pour until sake overflows and fills both containers.
Sake is sold in volume units divisible by 180 mL (a gō), the traditional Japanese unit for cup size: sake is traditional sold by the gō-sized cup, or in a 1.8 L (one shō, ten gō) sized flask. Today sake is also often sold in 720 mL (four gō) bottles – note that this is almost the same as the 750 mL standard for wine bottles, but is divisible into 4 gō.
In general, 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. In addition, sake stored at relatively high time can lead to formation of dicetopiperazine, a cyclo (Pro-Leu) that makes it bitter as it ages (Lecture Note, Oct. 2011). Sake has high microbiological stability due to its high content of ethanol. However, incidences of spoilage have been known to occur. One of the microoganisms implicated in this spoilage is lactic acid bacteria (LAB) that has grown tolerant to ethanol and is referred to as hiochi-bacteria (Suzuki et al., 2008). Sake stored at room temperature is best consumed within a few months after purchase.
After opening a bottle of sake, it is best consumed within 2 or 3 hours. It is possible to store sake in the refrigerator, but it is recommended to finish the sake within 2 days. This is because once premium sake is opened it begins to oxidize, which affects the taste. If the sake is kept in the refrigerator for more than 3 days, it will lose its “best” flavor. However, this does not mean it should be disposed of if not consumed. Generally, sake can keep very well and still taste just fine after weeks in the refrigerator. How long a sake will remain drinkable depends on the actual product itself, and whether it is sealed with a wine vacuum top.
Sake is often consumed as part of Shinto purification rituals (compare with the use of grape wine in the Christian Eucharist). Sakes served to gods as offerings prior to drinking are calledOmiki or Miki (お神酒, 神酒). People drink Omiki with gods to communicate with them and to solicit rich harvests the following year. During World War II, kamikaze pilots drank sake prior to carrying out their missions.
In a ceremony called kagami biraki, wooden casks of sake are opened with mallets during Shinto festivals, weddings, store openings, sports and election victories, and other celebrations. This sake, called iwai-zake (“celebration sake”), is served freely to all to spread good fortune.
At the New Year many Japanese people drink a special sake called toso. Toso is a sort of iwai-zake made by soaking tososan, a Chinese powdered medicine, overnight in sake. Even children sip a portion. In some regions, the first sips of toso are taken in order of age, from the youngest to the eldest.
- Amylolytic process
- Awamori, a distilled rice liquor produced in Okinawa
- Chuak, a Tripuri rice beer
- Mirin, an essential condiment used in Japanese cuisine, which has been drunk as a sweet sake
- Kohama style, a method of sake brewing
- Rice wine, a category including many different alcoholic drinks made from rice
- Shōchū, a distilled beverage, distinct from sake
- Tōji (brewmaster)
- Toso Spiced medicinal sake