納豆 is a traditional Japanese cuisine made from whole that have been fermented with Bacillus subtilis var. natto.
Nattō is often considered an acquired taste because of its powerful smell, strong flavor, and sticky, slimy texture.
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(c=豉), or
douchi (). 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, 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, which had the Chinese character 豉 (chǐ; soybean) written on it.
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 without the need for straw, thereby simplifying the commercial production of
nattō and enabling more consistent results.
Nutrition
Nattō is 55% water, 13%
, 19% protein, and 11%
fat (table). In a serving, nattō supplies 110
and is a rich source (20% or more of the
Daily Value, DV) of several dietary minerals, especially
iron (33% DV) and
manganese (73% DV), and
vitamin K (542% DV). Nattō contains some
B vitamins and
vitamin C 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 mustard if eaten from a commercially packaged nattō. Other ingredients such as long onion or kimchi 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, tamagoyaki, salad, as an ingredient in okonomiyaki, chahan, or even with spaghetti. 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, but less popular in Kansai.
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.
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 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 nattō is sold in small polystyrene 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 and , but if it is allowed to ferment too long, then ammonia is released.
The fermenting of nattō develops glutamic acid, which is why it has an umami flavour.
Related products
Many countries around Asia also produce similar traditional soybean foods fermented with Bacillus bacteria, such as shuǐdòuchǐ (水豆豉) of Chinese cuisine, cheonggukjang (청국장) of Korean cuisine, thua nao (ถั่วเน่า) of Thai cuisine, kinema of Nepalese cuisine and the regions of West Bengal and Sikkim, tungrymbai of Meghalaya, hawaijaar of Manipur, bekang um of Mizoram, akhuni of Nagaland, and piak of Arunachal Pradesh, Indian cuisine.
Gallery
File:Natto mixed.jpg| Nattō being stirred with chopsticks
File:Natto gunkan maki by LWY in Fukuoka.jpg| Nattō gunkan maki ( Nattō sushi)
File:納豆卵かけご飯 07.jpg| Nattō served on white rice with raw egg
File:Natto, with welsh onion and karashi by yoppy.jpg| Nattō topped with karashi mustard and negi onion
See also
