The nattō (納豆) is a traditional Japanese food made from whole soybeans fermented with Bacillus subtilis (natto variant) of yellow soybeans.
It is often served as a breakfast food with rice, eaten cold mixed with karashi mustard, soy sauce, or tara, and sometimes Japanese onion or kimchi.
In Japan, nattō is more popular in the eastern regions, including Kantō, Tōhoku, and Hokkaido.
Nattō has a distinctive odor, somewhat similar to that of a strong aged cheese. Mixing it produces many sticky threads.
Nattō is often eaten as nattō gohan (nattō on rice) and occasionally used in other foods, such as nattō sushi (nattōmaki), nattō toast, in miso soup, in tamagoyaki, in salads, as an ingredient in okonomiyaki, in chahan, or even with noodles.
Many find the taste unpleasant and smelly while others enjoy it as a delicacy.
A 2009 survey revealed that 70% of Japanese people find the taste pleasant, while others who may not find the taste of the food pleasant eat it anyway out of habit.
For those who do not like the smell and texture, “dried natto” and “fried natto” were developed around 1990. The smell and stickiness are reduced, making it easier to eat.
Another type of fermented soybeans called “Mamenoka (豆納香)” was developed by improving the varieties of soy and nattō bacilli to make them less sticky
Historically, domestic production was conducted using rice straw to retain moisture and as insulation, placing it in naturally warmer parts of the house or the fermentation shed, but is now performed with damp towels on glass pots or perforated plastic wrap on thermostat-controlled heating plates.
Home fermentation machines are also available.
The Japanese describe the sticky texture of nattō and other similar foods, like okura (okra), with the onomatopoeic word NEBA NEBA.
Rich in protein and vitamins, it has remarkable properties concerning cholesterol reduction. It also contains abundant vitamin K2.
- Difficulty: Difficult
- Cost: Very economical
- Rest time: 1 Day
- Preparation time: 10 Minutes
- Portions: 6Pieces
- Cooking methods: Boiling, Other
- Cuisine: Japanese
Ingredients
- 10.5 oz soybeans
- 1.1 lbs nattō-kin
Tools
Steps
Ensure that the entire process, including all utensils, pots, gauze, etc., is as sterile as possible.
Boil utensils for 5 minutes before use.
Wash the soybeans and soak them in 6 cups of water for 9-12 hours (longer soaking time recommended for colder months) to prepare them for fermentation.
Drain the soybeans from the soaking water.
Place the beans in a large pot, fill it with water, and boil for 2-3 hours, checking every half hour or so.
Rinse or immerse a colander, a spoon, and a casserole dish in boiling water to sterilize them.
In the sterilized colander, drain the cooked beans and place them in the sterilized casserole dish. Turn on the oven light so it preheats to 100°F.
Mix the nattō-kin starter with 3 tablespoons of boiled and cooled water.
While the beans are still warm, pour the natto spore packet over the beans. Mix the beans thoroughly using the sterilized spoon.
Spread the beans in a layer about 1 inch thick in the casserole dish.
N.B. If at any point during the process the grains spill onto the counter, etc., discard them to avoid contamination. It is crucial to maintain the purity of our ferment for the best final product.
Cover the dish well with a sheet of foil. Poke holes in the foil, spaced 1 inch apart.
Natto spores need some oxygen and darkness for ideal growing conditions
Place the covered casserole in the oven, in the dehydrator or another warming oven, and let the natto ferment for 22-24 hours, ensuring the temperature is consistently maintained at 100°F.
When a whitish film is seen and a smell of ammonia is noticed, it means the beans have finished fermenting.
At the end, let the Japanese natto cool at room temperature for 2 hours.
Remove the foil and store in the refrigerator in covered containers for at least overnight to achieve the best taste and thread-like texture.
It will last about a week in the refrigerator.
To eat it with rice: mix it well with chopsticks (at least 20 clockwise and counterclockwise turns).
I discovered the existence of nattō thanks to the wonderful television series “Shōgun“, based on the homonymous novel, in episode 4 “The Eightfold Fence” (see video).
Blackthorne is beginning to assimilate Japanese culture, speaking the language, developing relationships, and experiencing traditional Japanese cuisine.
During one scene, Blackthorne becomes curious to see the dish eaten by Mariko and Usami Fuji.
He insists on trying it and compares it to moldy cheese, which amuses the other two characters.
FAQ (Questions and Answers)
What is the commercial production process of nattō?
Nattō is made with soybeans, typically nattō soy.
Smaller beans are preferred, as the fermentation process can reach the center of the bean more easily.
The beans are washed and soaked in water for 12-20 hours to hydrate them and increase their size.
Subsequently, the soybeans are steam-cooked for 6 hours, although a pressure cooker can be used to reduce the time. The cooked beans are then mixed with the bacterium Bacillus subtilis, known as nattō-kin in Japanese.
From this point on, care must be taken to keep the ingredients away from impurities and other bacteria.
The mixture is allowed to ferment at 104°F for up to 24 hours. Subsequently, the nattō is cooled, then aged in the refrigerator for up to a week to allow for the development of the stringy texture.
Mass-produced nattō is sold in small polystyrene containers.
A typical package contains two, three, or occasionally four containers, each 40 to 50 g.
The smell of nattō comes from diacetyl and pyrazines, but if left to ferment too long, ammonia is released.
Nattō fermentation develops glutamic acid, which is why it has the elusive “savory” taste of umami.What are the origins of nattō?
A story about the origin of nattō attributes it to the samurai Minamoto no Yoshiie (1039–1106), who participated in a campaign in northeastern Japan between 1086 AD and 1088 AD.
One day, his troops were attacked while boiling soybeans for their horses. They hurriedly prepared the beans and opened the straw bags only a few days later, when the beans had already fermented.
The soldiers ate them anyway and liked the taste, so they offered some to Yoshiie, who also appreciated the taste.
Another story concerns Prince Shotoku (574–622), who is said to have wrapped leftover boiled soybeans in straw bags for his horse.
Since people ate these fermented beans and found them delicious, this type of stringy fermented beans soon gained popularity in Japan for its unique taste and strong flavor.What are other foods similar to nattō?
Before nattō, in China there was a similar dish made from fermented black soybeans called 豉 (chǐ) or douchi (Chinese: 豆豉; pinyin: dòuchǐ).
It is a seasoning made from whole salted, fermented, and aged soybeans invented in China and spread throughout East Asia.
Chinese use both black and yellow soybeans to produce douchi.
The amount of salt used differentiates it from nattō in taste and appearance.
The methods of soybean and rice cultivation were imported from China to Japan during the Yayoi period, and later the circulation of salt began to flourish in Japan.
This provided an opportunity for the production of douchi to become popular in Japan.
As salt was expensive at the time, it has been suggested that nattō was invented by chance during douchi production.
A wooden slip was found at Heijō-kyō on which the Chinese character 豉 (chǐ; soybeans) was written.
The excavation of the slurry is considered evidence supporting the hypothesis that the invention of nattō was based on 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.
Many Asian countries also produce traditional foods similar to fermented soybeans with Bacillus bacteria, such as cheonggukjang (청국장) from Korea, thua nao (ธั้วเน่า) from Thailand, kinema from Nepal, and the western Himalayan regions.
