How to Make Homemade Natto

Have you fallen in love with the surprising taste and texture of natto, and would like to learn how to make it yourself? Here’s how to prepare this gooey, delicious food at home.

Nattō is a traditional Japanese dish created from soybeans fermented using a bacteria called Bacillus subtilis var. natto.

It is usually eaten with plain rice. It is very rich in protein and nutrients (rich in vitamin K2), which makes it also good for its health benefits.

Its unique, strong and persistent flavour and sticky appearance can make it quite repulsive for those unaccustomed to it. But, for the same reasons, it has many fans!

How To Make Natto

Preliminary stage

Making natto is relatively easy, but there are a few points to note in terms of temperature and equipment cleanliness.

Utensils that come into contact with the starter and soybeans must be sterile. Before using, you can boil the utensils for 5 minutes or wash them in the dishwasher at high temperatures.

Natto fermentation temperatures range between 38 and 45°C (100 and 113°F). You can use a low temperature set oven, a large dehydrator, or a yogurt maker. Also, be aware that it will smell strong, so choose your incubation room carefully.

How To Make Natto

How to Make Homemade Natto

Nattō is a traditional Japanese dish with an addictive, gooey texture created from fermented soybeans. It is most often eaten with plain rice for lunch, dinner or supper.
4.75 of 4 ratings
Preparation Time 1 hr
Fermentation 12 hrs
Cuisine Japanese




Step 1: Cooking the Beans

  • Rinse the beans.
  • Soak the beans in water for 12 hours (24 hours if cold).
  • Drain the beans and place them in a large saucepan.
  • Cover the beans with water and cook them until the beans are tender. Alternatively (and even better), you can steam cook the beans for 45 minutes.

Step 2: Adding the Natto Culture

  • Boil 1/2 cup of water for 5 minutes, and allow it to cool for 10 minutes.
  • Add 1/5 teaspoon of natto starter culture (0.1 g or 1 ml) to water and mix well.
  • Once the beans are cooked, drain them, then place them in a large bowl.
  • Add the culture inoculated water while the beans are still very hot (around 80°C/175°F). It is important to add the natto spores while the beans are still very hot, because the heat shock will start the Bacillus spores germination and at the same time kill any unwanted bacteria.
  • Mix very well with a large spoon.

Step 3: Incubation

  • Preheat your incubator at 40°C/105°F (oven, dehydrator, or yogurt-maker).
  • Add a thin layer of beans to each container.
  • Place a fabric on top of each container and attach the plastic film to the fabric.
  • Place the containers in the incubator and ferment for 12 hours.
  • You can ferment for up to 24 hours if you like a stronger taste or aromas. You need to keep your incubator at 40°C/105°F.


You can eat natto immediately, but its quality will improve if you keep it in the fridge for a few days. Eat it early the next morning as a Japanese-style breakfast.
Keyword Natto Recipe
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