What Is Natto? A Complete Guide

“It’s certainly an acquired taste for North American taste buds, but in Japan it’s eaten at any and all times of day,” says Jennifer Akimoto, RD, a registered dietitian of Japanese heritage who is based in Ontario. “With its many health benefits, you may want to consider adding it to your diet, too.”

Types of Natto

• Otsubu This kind of natto is made from larger soybeans, and is typically moderately sticky. It can be served as a main or side dish. Natto made this way is more pungent, creamy, and chewy.
• Kotsubu Stickier than otsubu, kotsubu pairs well with rice. It is made from smaller soybeans than otsubu and has a milder flavor.
• Hikiwari Made with crushed soybeans, this type of natto has a smooth texture. It can be used to make maki rolls.

“They all vary slightly in flavor and texture, so try a few before you decide if you like it or not,” says Akimoto.

Natto Nutrition Facts

Natto offers other health benefits as well. “It has a lot of nutrition packed within a small serving,” says Melanie Marcus, RD, a registered dietitian from the greater Charlotte, North Carolina, area. “It’s a great source of protein for vegans or anyone trying to follow a plant-based lifestyle.”

Potential Health Benefits of Natto

May Strengthen Bones

It’s important to note that supplements may contain much higher doses of vitamin K than natto, so it’s not clear if the soybean food would have the same effects as the doses used in research studies.

Beneficial for Heart Health

May Improve Digestion

Can Natto Help With Weight Loss?

Natto is high in protein and fiber, which Akimoto calls a “hunger-crushing combo.” Feeling satiated after meals can lessen the desire to munch on unhealthy snacks.

How to Select and Store Natto

“Make sure to thaw natto before eating it,” Akimoto says.

Natto should be stored in the refrigerator in an airtight container, Sabat says.

How to Eat Natto

In Japan, natto is a popular breakfast food, but it can be enjoyed any time of day, Akimoto says.

“If you’re having it for the first time, try it on top of rice or toast with a sprinkle of green onions on top,” she recommends. “This is how it’s traditionally eaten in Japan.”

It’s considered good practice to stir natto before eating. “Experienced natto eaters would tell you to stir the natto at least 100 times before you eat it in order to develop the ‘froth’ and umami flavor,” Akimoto says.

Health Risks of Natto

Natto is generally considered safe for most people to eat, but some people may experience digestive issues such as bloating and gas, Sabat says.

Since natto is made from fermented soybeans, it is not appropriate for anyone with a soy allergy, Marcus notes.

Tips for Making Your Own Natto

If you want to make natto at home, you will need soybeans and Bacillus subtilis, a bacteria starter. You can also use natto from a previous batch as a starter for the next batch.

“It’s a set-it-and-forget-it prep style that takes about two or three days from start to finish,” says Sabat.

First, you’ll cook the soybeans in an Instant Pot, pressure cooker, or on the stove. After draining them, you’ll add the bacteria starter (or natto from a previous batch) and let the mixture ferment for 24 hours in a fermentation box or yogurt maker at 40 degrees C (about 104 degrees F). The next day you’ll need to move the natto to the fridge to continue its fermentation for another 24 hours before it’s ready to eat.

The Takeaway

• Natto is a nutrient-dense traditional Japanese food made from fermented soybeans. It has a sticky texture, an umami taste, and a strong smell.
• Natto may be beneficial for your bones, heart, and digestive system. It’s a good source of vitamin K2, and it also contains fiber, which makes it a healthy food choice if you’re trying to lose weight.
• Natto can be made at home or purchased in Asian grocery stores. Pay attention to the expiration date on the label, and store it in the refrigerator in an airtight container.