is a traditional
Japanese food made from whole
soybean
The soybean, soy bean, or soya bean (''Glycine max'') is a species of legume native to East Asia, widely grown for its edible bean. Soy is a staple crop, the world's most grown legume, and an important animal feed.
Soy is a key source o ...
s that have been
fermented
Fermentation is a type of anaerobic metabolism which harnesses the redox potential of the reactants to make adenosine triphosphate (ATP) and organic end products. Organic compound, Organic molecules, such as glucose or other sugars, are Catabo ...
with
''Bacillus subtilis'' var. ''natto''.
It is often served as a breakfast food with rice.
It is served with
''karashi'' mustard,
soy
The soybean, soy bean, or soya bean (''Glycine max'') is a species of legume native to East Asia, widely grown for its edible bean. Soy is a staple crop, the world's most grown legume, and an important animal feed.
Soy is a key source of f ...
or
''tare'' sauce, and sometimes
Japanese bunching onion. Within Japan, ''nattō'' is most popular in the eastern regions, including
Kantō,
Tōhoku, and
Hokkaido
is the list of islands of Japan by area, second-largest island of Japan and comprises the largest and northernmost prefectures of Japan, prefecture, making up its own list of regions of Japan, region. The Tsugaru Strait separates Hokkaidō fr ...
.
''Nattō'' is often considered an
acquired taste
An acquired taste is an appreciation for something unlikely to be enjoyed by a person who has not had substantial exposure to it. It is the opposite of innate taste, which is the appreciation for things that are enjoyable by most people without p ...
because of its powerful smell, strong flavor, and sticky, slimy texture.
A 2009 survey revealed that 70% of the 3,827 respondents (0.003% of the population) found the taste pleasant, and others who may not find the taste pleasant still eat the food out of habit.
History

Sources differ about the earliest origin of ''nattō''. One theory is that nattō was codeveloped in multiple locations in the distant past, since it is simple to make with ingredients and tools commonly available in Japan since ancient times.
Legendary origins
One story about the origin of ''nattō'' attributes it to the samurai
Minamoto no Yoshiie (1039–1106), who was on a campaign in northeastern Japan between 1086 and 1088 AD. One day, his troops were attacked while boiling soybeans for their horses. They hurriedly packed up the beans, and did not open the straw bags until a few days later, by which time the beans had fermented. The soldiers ate it anyway, and liked the taste, so they offered some to Yoshiie, who also liked the taste.
Another story involves
Prince Shotoku (574–622), who is said to have wrapped the leftovers of boiled soybeans in straw bags for his horse. As people happened to eat these fermented beans and found them delicious, this type of fermented stringy beans soon gained popularity in Japan because of its unique taste and strong flavor.
Chinese ''douchi''
Before ''nattō'', there was a similar dish of fermented black soybeans food in China called ''shì'', ''chǐ''( zh, c=豉), or ''
douchi
''Douchi'' is a type of fermented and salted black soybean most popular in the cuisine of China, where they are most widely used for making black bean sauce dishes. Shurtleff, W.; Aoyagi, Abr>History of Fermented Black Soybeans (165 B.C. to ...
'' (). These are salted, fermented and aged whole soybean seasonings or condiments invented in China and spread throughout East Asia. They are usually made from fermented soybeans and with an ample amount of salt; however, the ingredients and production methods differ in Japan. Chinese use both black and yellow soybeans to produce ''douchi''. The amount of salt used also differentiates ''douchi'' and ''nattō'' in taste and appearance.
The cultivation methods of soybeans and rice were imported from China to Japan during the
Yayoi period
The Yayoi period (弥生時代, ''Yayoi jidai'') (c. 300 BC – 300 AD) is one of the major historical periods of the Japanese archipelago. It is generally defined as the era between the beginning of food production in Japan and the emergence o ...
, and later on, the circulation of salt began to flourish in Japan. This provided an opportunity for the production of ''douchi'' to become popular in Japan. Because salt was expensive at the time, it has been suggested that ''nattō'' was invented by accident during the production of ''douchi.''
A wooden slip was excavated in
Heijō-kyō
was the Capital of Japan during most of the Nara period, from 710 to 740 and again from 745 to 784. The imperial palace is a listed UNESCO World Heritage together with other places in the city of Nara (cf. Historic Monuments of Ancient ...
, which had the Chinese character 豉 (chǐ; soybean) written on it.
The excavation of the slip is considered an evidence to support the hypothesis that the invention of ''nattō'' was based on the Chinese ''douchi'' imported to Japan.
The Chinese character 豉 entered Japan in the 8th century. It was pronounced "kuki" until the 11th century, when ''nattō'' became a new name for fermented soybeans.
Commercialization in the Taisho period
A change in the production of ''nattō'' occurred in the
Taishō period (1912–1926), when researchers discovered a way to produce a ''nattō''
starter culture containing ''
Bacillus subtilis
''Bacillus subtilis'' (), known also as the hay bacillus or grass bacillus, is a gram-positive, catalase-positive bacterium, found in soil and the gastrointestinal tract of ruminants, humans and marine sponges. As a member of the genus ''Bacill ...
'' without the need for straw, thereby simplifying the commercial production of ''nattō'' and enabling more consistent results.
Nutrition
Nattō is 55% water, 13%
carbohydrate
A carbohydrate () is a biomolecule composed of carbon (C), hydrogen (H), and oxygen (O) atoms. The typical hydrogen-to-oxygen atomic ratio is 2:1, analogous to that of water, and is represented by the empirical formula (where ''m'' and ''n'' ...
s, 19%
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...
, and 11%
fat
In nutrition science, nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such chemical compound, compounds, most commonly those that occur in living beings or in food.
The term often refers specif ...
(table). In a serving, nattō supplies 110
calorie
The calorie is a unit of energy that originated from the caloric theory of heat. The large calorie, food calorie, dietary calorie, kilocalorie, or kilogram calorie is defined as the amount of heat needed to raise the temperature of one liter o ...
s and is a rich source (20% or more of the
Daily Value
In the U.S. and Canada, the Reference Daily Intake (RDI) is used in nutrition labeling on food and dietary supplement products to indicate the daily intake level of a nutrient that is considered to be sufficient to meet the requirements of 97� ...
, DV) of several
dietary minerals
In the context of nutrition, a mineral is a chemical element. Some "minerals" are essential for life, but most are not. ''Minerals'' are one of the four groups of essential nutrients; the others are vitamins, essential fatty acids, and essen ...
, especially
iron
Iron is a chemical element; it has symbol Fe () and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's o ...
(33% DV) and
manganese
Manganese is a chemical element; it has Symbol (chemistry), symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese was first isolated in the 1770s. It is a transition m ...
(73% DV), and
vitamin K
Vitamin K is a family of structurally similar, fat-soluble vitamers found in foods and marketed as dietary supplements. The human body requires vitamin K for post-translational modification, post-synthesis modification of certain proteins ...
(542% DV). Nattō contains some
B vitamins
B vitamins are a class of water-soluble vitamins that play important roles in Cell (biology), cell metabolism and synthesis of red blood cells. They are a chemically diverse class of compounds.
Dietary supplements containing all eight are referr ...
and
vitamin C
Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits, berries and vegetables. It is also a generic prescription medication and in some countries is sold as a non-prescription di ...
in moderate amounts (table).
Appearance and consumption
''Nattō'' has a distinctive odor, somewhat akin to a pungent aged cheese. Stirring ''nattō'' produces many sticky strings.
[ The dish is eaten cold with rice, mixed with the included soy sauce or ]karashi
, also known as '' oni karashi'', is a type of mustard used as a condiment or as a seasoning in Japanese cuisine. ''Karashi'' is made from the crushed seeds of '' Brassica juncea'' (brown mustard) and is usually sold in either powdered or paste ...
mustard if eaten from a commercially packaged ''nattō''. Other ingredients such as long onion or kimchi
Kimchi (; ) is a traditional Korean side dish (''banchan'') consisting of salted and fermented vegetables, most often napa cabbage or Korean radish. A wide selection of seasonings are used, including '' gochugaru'' (Korean chili powder), ...
are often added.
''Nattō'' is frequently eaten as ''nattō'' ''gohan'' (''nattō'' on rice). ''Nattō'' is occasionally used in other foods, such as ''nattō'' sushi (nattōmaki), ''nattō'' toast, in miso soup
is a traditional Japan, Japanese soup consisting of miso paste mixed with a ''dashi'' Stock (food), stock. It is commonly served as part of an meal, meaning "one soup, three dishes," a traditional Japanese meal structure that includes rice, sou ...
, tamagoyaki, salad, as an ingredient in okonomiyaki
is a Japanese ''teppanyaki'' savory pancake dish consisting of wheat flour batter and other ingredients (mixed, or as toppings) cooked on a '' teppan'' (flat griddle). Common additions include cabbage, meat, and seafood, and toppings include ...
, chahan, or even with spaghetti
Spaghetti () is a long, thin, solid, cylindrical pasta.[spaghetti](_blank)
Dictionary.com. Dictionary.com Una ...
. Sometimes soybeans are crushed before fermenting.
Many find the taste unpleasant and smelly while others relish it as a delicacy. Nattō is more popular in some areas of Japan than in others. ''Nattō'' is known to be popular in the eastern Kantō region
The is a geography, geographical region of Honshu, the largest island of Japan. In a common definition, the region includes the Greater Tokyo Area and encompasses seven prefectures of Japan, prefectures: Chiba Prefecture, Chiba, Gunma Prefe ...
, but less popular in Kansai
The or the lies in the southern-central region of Japan's main island Honshū. The region includes the prefectures of Nara, Wakayama, Kyoto, Osaka, Hyōgo and Shiga, often also Mie, sometimes Fukui, Tokushima and Tottori. The metropoli ...
.
For those who dislike the smell and texture of natto, "dried natto" and "fried natto" were developed around 1990. The smell and stickiness are reduced, making it easier to eat for those who do not like conventional natto. Another type of fermented soybeans called ''mamenoka'' () has also been developed by improving the soybean and natto bacillus varieties to make it less sticky.
Production process
Commercial
''Nattō'' is made from soybeans, typically ''nattō'' soybeans. Smaller beans are preferred, as the fermentation process will be able to reach the center of the bean more easily. The beans are washed and soaked in water for 12 to 20 hours to hydrate them, and increase their size. Next, the soybeans are steamed
Steaming is a method of cooking using steam. This is often done with a food steamer, a kitchen appliance made specifically to cook food with steam, but food can also be steamed in a wok. In the American Southwest, steam pits used for cooking ha ...
for six hours, although a pressure cooker
A pressure cooker is a sealed vessel for cooking food with the use of high pressure steam and water or a water-based liquid, a process called pressure cooking. The high pressure limits boiling and creates higher temperatures not possible at low ...
may be used to reduce the time. The cooked beans are mixed with the bacterium ''Bacillus subtilis
''Bacillus subtilis'' (), known also as the hay bacillus or grass bacillus, is a gram-positive, catalase-positive bacterium, found in soil and the gastrointestinal tract of ruminants, humans and marine sponges. As a member of the genus ''Bacill ...
'', known as ''nattō-kin'' in Japanese. From this point on, care must be taken to keep the ingredients away from impurities and other bacteria
Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...
. The mixture is fermented at for up to 24 hours. Afterward, the ''nattō'' is cooled, then aged in a refrigerator for up to one week to allow the development of stringiness.
In ''nattō''-making facilities, these processing steps have to be done while avoiding incidents in which soybeans are touched by workers. Even though workers use ''B. subtilis natto'' as the starting culture, which can suppress some undesired bacterial growth, workers pay extra-close attention not to introduce skin flora
Skin flora, also called skin microbiota, refers to microbiota (community (ecology), communities of microorganisms) that reside on the skin, typically human skin.
Many of them are bacterium, bacteria of which there are around 1,000 species upon hu ...
onto soybeans.
Home
''Nattō'' continues to be a popular home fermentation activity with some families starting new batches daily. Home production was historically done using rice straw to maintain moisture and as insulation with placement in naturally warmer parts of the home or fermentation shed, but is now done with moist towels over glass pans or perforated plastic wrap on thermostat-controlled heating pads. At-home fermentation machines are also available but are rarely marketed specifically for ''nattō'', which is a less finicky culture capable of sustaining its own ideal temperature once it gets going.
End product
Mass-produced
Mass production, also known as mass production, series production, series manufacture, or continuous production, is the production of substantial amounts of standardized products in a constant flow, including and especially on assembly lines. ...
''nattō'' is sold in small polystyrene
Polystyrene (PS) is a synthetic polymer made from monomers of the aromatic hydrocarbon styrene. Polystyrene can be solid or foamed. General-purpose polystyrene is clear, hard, and brittle. It is an inexpensive resin per unit weight. It i ...
containers. A typical package contains two, three, or occasionally four containers, each . One container typically complements a small bowl of rice.
''Nattō'' odor comes from diacetyl
Diacetyl ( ; IUPAC systematic name: butanedione or butane-2,3-dione) is an organic compound with the chemical formula (CH3CO)2. It is a yellow liquid with an intensely buttery flavor. It is a vicinal diketone (two C=O groups, side-by-side). Di ...
and pyrazine
Pyrazine is a heterocyclic aromatic organic compound with the chemical formula C4H4N2. It is a symmetrical molecule with point group D2h. Pyrazine is less basic than pyridine, pyridazine and pyrimidine. It is a ''"deliquescent crystal or wax-lik ...
s, but if it is allowed to ferment too long, then ammonia
Ammonia is an inorganic chemical compound of nitrogen and hydrogen with the chemical formula, formula . A Binary compounds of hydrogen, stable binary hydride and the simplest pnictogen hydride, ammonia is a colourless gas with a distinctive pu ...
is released.
The fermenting of ''nattō'' develops glutamic acid
Glutamic acid (symbol Glu or E; known as glutamate in its anionic form) is an α- amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a non-essential nutrient for humans, meaning that the human body can ...
, which is why it has an umami
Umami ( from ), or savoriness, is one of the five basic tastes. It is characteristic of broths and cooked meats.
People taste umami through taste receptors that typically respond to glutamates and nucleotides, which are widely present in me ...
flavour.
Related products
Many countries around Asia also produce similar traditional soybean foods fermented with ''Bacillus'' bacteria, such as ''shuǐdòuchǐ'' (水豆豉) of China
China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...
, '' cheonggukjang'' (청국장) of Korea
Korea is a peninsular region in East Asia consisting of the Korean Peninsula, Jeju Island, and smaller islands. Since the end of World War II in 1945, it has been politically Division of Korea, divided at or near the 38th parallel north, 3 ...
, '' thua nao'' (ถั่วเน่า) of Thailand
Thailand, officially the Kingdom of Thailand and historically known as Siam (the official name until 1939), is a country in Southeast Asia on the Mainland Southeast Asia, Indochinese Peninsula. With a population of almost 66 million, it spa ...
, '' kinema'' of Nepal
Nepal, officially the Federal Democratic Republic of Nepal, is a landlocked country in South Asia. It is mainly situated in the Himalayas, but also includes parts of the Indo-Gangetic Plain. It borders the Tibet Autonomous Region of China Ch ...
and the Himalaya
The Himalayas, or Himalaya ( ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the Earth's highest peaks, including the highest, Mount Everest. More than 100 pea ...
n regions of West Bengal
West Bengal (; Bengali language, Bengali: , , abbr. WB) is a States and union territories of India, state in the East India, eastern portion of India. It is situated along the Bay of Bengal, along with a population of over 91 million inhabi ...
and Sikkim
Sikkim ( ; ) is a States and union territories of India, state in northeastern India. It borders the Tibet Autonomous Region of China in the north and northeast, Bhutan in the east, Koshi Province of Nepal in the west, and West Bengal in the ...
, '' tungrymbai'' of Meghalaya
Meghalaya (; "the abode of clouds") is a states and union territories of India, state in northeast India. Its capital is Shillong. Meghalaya was formed on 21 January 1972 by carving out two districts from the Assam: the United Khasi Hills an ...
, ''hawaijaar'' of Manipur
Manipur () is a state in northeastern India with Imphal as its capital. It borders the Indian states of Assam to the west, Mizoram to the south, and Nagaland to the north and shares the international border with Myanmar, specifically t ...
, ''bekang um'' of Mizoram
Mizoram is a states and union territories of India, state in northeastern India, with Aizawl as its Capital city, capital and largest city. It shares 722-kilometres (449 miles) of international borders with Bangladesh to the west, and Myanmar t ...
, '' akhuni'' of Nagaland
Nagaland () is a States and union territories of India, state in the northeast India, north-eastern region of India. It is bordered by the Indian states of Arunachal Pradesh to the north, Assam to the west, Manipur to the south, and the Naga Sel ...
, and ''piak'' of Arunachal Pradesh
Arunachal Pradesh (; ) is a States and union territories of India, state in northeast India. It was formed from the North-East Frontier Agency (NEFA) region, and India declared it as a state on 20 February 1987. Itanagar is its capital and la ...
, India
India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...
.
Gallery
File:Natto mixed.jpg, ''Nattō'' being stirred with chopsticks
File:Natto gunkan maki by LWY in Fukuoka.jpg, ''Nattō gunkan maki'' (''Nattō'' sushi
is a traditional Japanese dish made with , typically seasoned with sugar and salt, and combined with a variety of , such as seafood, vegetables, or meat: raw seafood is the most common, although some may be cooked. While sushi comes in n ...
)
File:納豆卵かけご飯 07.jpg, ''Nattō'' served on white rice with raw egg
Humans and other Hominidae, hominids have consumed Egg, eggs for millions of years. The most widely consumed eggs are those of fowl, especially chickens. People in Southeast Asia began harvesting chicken eggs for food by 1500 BCE. Eggs of oth ...
File:Natto, with welsh onion and karashi by yoppy.jpg, ''Nattō'' topped with karashi
, also known as '' oni karashi'', is a type of mustard used as a condiment or as a seasoning in Japanese cuisine. ''Karashi'' is made from the crushed seeds of '' Brassica juncea'' (brown mustard) and is usually sold in either powdered or paste ...
mustard and negi onion
See also
*
*
* Cheonggukjang – Traditional Korean food made by fermenting soybeans.
* Other fermented soy foods include soy sauce
Soy sauce (sometimes called soya sauce in British English) is a liquid condiment of China, Chinese origin, traditionally made from a fermentation (food), fermented paste of soybeans, roasted cereal, grain, brine, and ''Aspergillus oryzae'' or ''A ...
, Japanese miso
is a traditional Japanese seasoning. It is a thick paste produced by fermenting soybeans with salt and kōji (the fungus ''Aspergillus oryzae''), and sometimes rice, barley, seaweed, or other ingredients. It is used for sauces and spreads; p ...
and fermented tofu
or bean curd is a food prepared by Coagulation (milk), coagulating soy milk and then pressing the resulting curds into solid white blocks of varying softness: ''silken'', ''soft'', ''firm'', and ''extra (or super) firm''. It originated in Chin ...
.
*
*
*
* Kinema traditional Nepalese food made from fermented soybean
* Nattokinase
References
{{DEFAULTSORT:Natto
Fermented soy-based foods
Japanese cuisine terms
Japanese inventions
Japanese cuisine
Buddhist cuisine
Articles containing video clips