Natto

What is Natto?

Natto is made by fermenting soybeans with a bacterium called Bacillus subtilis. The finished beans are sticky and covered in long, stringy threads when stirred. Natto has a strong, pungent smell, sometimes compared to aged cheese, and a flavor that many people find intense. It is usually served cold, often over a bowl of steamed rice, and may be topped with mustard, soy sauce, or chopped green onion. The texture is slippery and the taste is savory with a hint of umami.

Where does Natto come from?

The beginnings of natto are not fully clear, with some believing it arose independently in several places in Japan. One legend links its discovery to a samurai, Minamoto no Yoshiie, whose soldiers accidentally fermented soybeans while on campaign. Another story credits Prince Shotoku, who is said to have wrapped leftover beans in straw for his horse, leading to fermentation. Natto may have connections to Chinese douchi, a salted, fermented soybean product, but differs in its use of less salt and different methods.

How is Natto made?

To make natto, soybeans are first soaked in water to plump them up, then steamed until soft. The warm beans are mixed with Bacillus subtilis, a bacterium that triggers fermentation. The mixture is kept warm for about a day, then cooled and aged in the refrigerator for several days to develop its characteristic stickiness. Today, natto is often made in factories using starter cultures, without the need for straw.

How and when is Natto eaten?

Natto is most commonly eaten at breakfast in Japan, served cold on top of rice. It is often mixed with soy sauce or tare (a sweetened soy-based sauce), spicy karashi mustard, and sometimes sliced green onion. Some people add other toppings like kimchi. Natto can also be used in sushi rolls, on toast, in omelets, or mixed into soups and salads. While many enjoy its flavor and texture, others eat it mainly out of habit or for its nutritional value.

Kinds of Natto

Most natto is made with whole soybeans, but sometimes the beans are crushed before fermentation. In recent decades, dried and fried versions have been developed for those who dislike the strong smell and sticky texture. Another type called mamenoka uses a different strain of bacteria to produce a less stringy result. Natto is most popular in eastern Japan, while other regions may prefer different fermented soybean foods.

What Natto means

Natto is a staple in many Japanese households, especially in the east. It is known for dividing opinion due to its smell and texture, and is often described as an acquired taste. Despite this, it remains a regular part of breakfast for many. Natto is valued for its high protein and vitamin K content. Its production became more widespread and consistent after the development of starter cultures in the early 20th century.

Questions people ask about Natto

Good reading and sources

• BBC News - Japan opens 98th national airport in IbarakiBBC, Article

• Natto on WikipediaEncyclopedia
• More photos on Wikimedia CommonsPhotos
• Wikidata recordOpen data