Natto

Japanese Food: Mito Natto, Ibaraki Prefecture 水戸 納豆 茨城県

by Johannes Schonherr

A basic traditional Japanese breakfast consists of a bowl of rice, a bowl of miso soup, some pickles and nori, dried seaweed. At ryokan, traditional Japanese inns, you are usually also served a slice of shio sake, dried, salty salmon.

Wara natto on sale in Kairaku-en Park, Mito, Ibaraki Prefecture.
Wara natto on sale in Kairaku-en Park, Mito, Ibaraki Prefecture
Opening a pack of wara natto, Ibaraki Prefecture, Japan.
Opening a pack of wara natto

In eastern Japan, in the Kanto and Tohoku regions, a typical breakfast rice topping is natto. Natto consists of fermented soybeans, is has a strong smell and when you move it with your chopsticks, it draws slimy strings.

Mix the natto with karashi mustard and soy sauce and some negi cuts (Welsh onion), then put it on your rice, and mix it into the rice. Some people also mix their natto with a raw egg.

There are of course many other dishes that involve natto. Natto can be rolled into maki sushi, onigiri rice balls can be filled with natto, it can be added to miso soup, in salads, it can even be eaten with spaghetti.

One of the most innovative and most delicious uses of natto is sakura natto, horse meat tartar mixed with natto and a raw egg. It's a specialty you will only find in Kumamoto, a city famous for its horse meat dishes.

Natto is considered to be very healthy. It contains various vitamins, manganese, iron, fibers and other things nutritionists like to talk about.

More importantly, however, is the question: "What does it taste like"? Well, natto is certainly an acquired taste but if you like smelly cheese, kimchi and pitan (fermented eggs), you will certainly like it.

As popular as natto is in eastern Japan, in western Japan, in Kansai and further west, many people dislike its taste, smell and appearance though it is generally available and part of some local specialties like the horse meat dish in Kumamoto, Kyushu.

Opening a pack of wara natto, Ibaraki Prefecture, Japan.
Emptying a pack of wara natto
Natto and cut Welsh onion on rice.
Natto and cut Welsh onion on rice

Mito - the Natto Capital

The city most famous for quality natto is Mito in Ibaraki Prefecture, in the north of Kanto. At Mito Station and in the area around it, plenty of shops sell various types of natto. Especially wara natto is popular in Mito, the most traditional type of natto, wrapped in rice straw.

You can buy wara natto at many outlets all over the city, including the city's landmark Kairaku-en Park, you will also find it at nearby popular spots like the Yamasa Fish Market in Nakaminato, close to the Aqua World Aquarium, another major attraction of the Mito area.

In Tokyo, original Mito natto is on sale at the Tsukiji Fish Market.

What has made Mito the natto capital of Japan? Ibaraki Prefecture has a long and strong history in natto production and once the Joban train line opened in 1900, directly connecting Mito with Tokyo, merchants began to sell large amounts of natto, right at the station to travelers arriving from the capital.

They took it back to their families, friends, and workplaces all over Tokyo and Kanto and thus word spread quickly that Mito natto wasn't just ordinary natto but a particularly tasty natto.

Sign at the Takano Food natto factory.
Sign at the entrance of the Takano Food natto factory in Noda, near Mito, Ibaraki Prefecture

Natto History and Natto Fermentation

There are no definite records on how natto originally became part of the Japanese cuisine.

The fermentation process that turns steamed or boiled soy beans into natto is caused by a bacteria named Bacillus subtilis natto, known in Japanese as natto-kin. One of the favored habitats of natto-kin is rice straw.

Rice straw was available in abundance in Japan in ancient times. In the Nara and Heian periods, more than a 1,000 years ago, it became fashionable to wrap food in rice straw for transportation.

Food wrapped in rice straw also became a favorite form of presentation as a gift.

Some natto historians claim that that is the origin of natto. Someone intended to present someone with a present of boiled soy beans - but during transport the beans had turned into natto.

Another tale tells of an army going to Tohoku in Heian times, fighting local lords. The soldiers were boiling soy beans when they were attacked by the enemy. They quickly wrapped the beans into rice straw and made a retreat.

When they opened the straw packages days later, they discovered that the beans had turned soft and smelly and were connected by slimy strings. The soldiers ate them anyway - and they liked them. So did their leader when presented with the beans.

Be it as it may, natto has been around in Japan since at least the Heian Period (794-1185).

Farmers steamed or boiled the soy beans, packed them into rice straw and let the bacteria do their work. The natto was sold still in its straw packages.
Traditional farmers still make their own natto that way today.

In the Taisho Period (1912-1926) however, researchers found a way to artificially grow Bacillus subtilis natto in the laboratory without the need for any straw. Injected into pots of steamed soy beans, the new lab-grown bacteria worked as a reliable starter culture, finally allowing mass production of natto.

From then on, natto could efficiently be manufactured using industrial-size equipment such as large steaming / boiling caldrons. With the right amount of bacteria added, the steamed beans could then mature in any form of clean, non-corrosive container.

Wara natto on sale in Kairaku-en Park, Mito, Ibaraki Prefecture.
Wara natto on sale in Kairaku-en Park, Mito, Ibaraki Prefecture

Mass Production Natto Today

Today, most natto is produced in fully automated squeaky clean factories. After soaking in water for several hours and following steaming of the beans, the Bacillus subtilis natto is added.

The beans are packed by machines into the Styrofoam containers that will eventually reach the consumer.

Machines place small plastic-wrapped packages of soy sauce and karashi mustard into the containers before they are taken to the fermentation room.

There, in the perfect fermentation temperature (about 40°C) and directly in the plastic containers, the bacteria do their work. After up to 24 hours, when the fermentation process is completed, the containers go to the cooler room where the natto matures for up to a week. Finally, the small Styrofoam containers go the packaging room. Usually, three of them are bundled together as a retail item.

A bundle of three small natto containers, holding about 40 to 50 grams of natto per container, costs about 80 yen to 130 yen at a Kanto area supermarket.

Mito Wara Natto

While natto in Styrofoam containers can be found in any supermarket in Japan, wara natto, natto sold in rice straw is today considered the trademark Mito natto.

The by far biggest manufacturer of wara natto is named the Mito Natto Company (Mito Natto Seizo Kabushiki Kaisha), the brand name of their natto is simply Mito Natto. The vast majority of rice-straw-packaged natto sold commercially today is produced by the Mito Natto Company.

After most other local producers opted for the plastic container variation, the Mito Natto Company decided to stay with the tradition - as much as industrial production would allow.

The Mito Natto Company can't possibly rely on the accidental fermentation via the rice straw. Lab-based natto-kin is used to assure a consistent quality output but the fermentation and maturing does take place directly in the rice straw - giving their product a unique, traditional aroma.

Add to that the pleasure of opening a traditional rice straw package - it feels like you are getting the real natto experience. The sight and smell of the rice straw alone sets this natto apart. That's the natto Mito is most famous for today.

Mito Natto Company website in Japanese www.mitonatto.com

Mito Tengu Natto

Much smaller is the Mito Tengu Natto Company (Mito Tengu Natto Sasanuma Goro Shoten). Though their product can only rarely be found in the markets, they operate a museum displaying and demonstrating the details of wara natto, its history and its production in the past and the present.

Mito Tengu Natto Museum
3-4-30 Sannomaru, Mito-shi  (about a 400m walk from Mito Station)
Tel: 029 225 2121

Open daily from 9 am to 5.30 pm.
Admission free.

The museum is located in a building next to the actual Mito Tengu Natto factory. You can watch the workers through a glass wall.

Mito Tengu Natto website www.tengunatto.jp (in Japanese)

A container of Takano Food Okame Natto.
A container of Takano Food Okame Natto. Packs of soy sauce and karashi mustard are inside of each container

Takano Foods

Takano Foods is today one of the biggest natto producers in Japan. Starting out as a small natto manufacturer in Ibaraki Prefecture early in the 20th century, Takano Foods today runs industrial production facilities across the country. Their main production plant is located in Noda, Omitama City, close to Mito.

Their natto brand name is Okame Natto. It's easily recognizable by its logo, the face of an ancient goddess named Okame. Resembling a kagura-mask, the face is printed onto every natto package the company sells, across all the various types of natto on offer.

Okame Natto is today generally sold in Styrofoam containers. It's said that when you open any family fridge in Kanto, you will find a pack of Okame Natto inside. That's how widespread their natto is.
The Takano Foods plant in Noda near Mito produces 2 million packages per day, 365 days per year.

Takano Foods operates a small but informative museum at its Noda Factory. Information on the exhibits is only in Japanese. Factory tours (in Japanese) are available on request.

Takano Foods Natto Factory / Museum access:

1542, Noda, Omitama-shi, Ibaraki Prefecture
Tel: 0120 58 7010

The museum is open daily from 9 am to 4 pm. Closed over the New Year holidays. Admission is free.

Factory tours are available during the same time. Reservation required.

The closest train station is Ishioka on the JR Joban Line (about 1 hour from Ueno Station by express train). From Ishioka Station it is about 30 minutes by taxi.

Takano Foods Japanese-language website


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