Secret Recipe: How To Make Natto?

When it comes to Japan, we always expect to find one of the kind experience in the world, including food. Japanese cuisines sometimes make people hesitate to try. But if you give it a chance, you will recognize that it is nothing but tasty and delicious. Natto, a popular breakfast dish is one of those cuisines. So what is natto? And how to make Natto at home? Let’s follow this blog to find out.

1. Things You Need To Know About Natto

How to make natto

Natto is known for its slippery texture

Natto or Japanese fermented soybeans is a very famous breakfast dish in Japan. What makes it one of the strangest Japanese dish lies in its slippery texture and a quite pungent smell. The origin of Natto dated back to 1000 years ago. No one knows exactly how it was created. There are several theories, but the most well-known one is related to Hachiman Taro Yoshiie, a Japanese general. It is said that, while Yoshiie was cooking soybeans for his horse, there was a sudden attack. He immediately grabbed the food and tied it to the back of the horse. A few days later, the warmth from the horse’s body fermented soybeans. They decided to give it a try and it turned out delicious. So Natto was born around that time.

2. How To Make Natto?

Natto is widely enjoyed all over Japan, so it’s not a problem to find a store selling this dish. But if you are into cooking and want to prepare a high-quality supplement dish for your family, you can totally make homemade Natto. In case you are wondering how to make Natto, hope that you’ll find out the answer through this blog.

Some Notes Before Starting:

  • All the equipment (pot, spoons, containers,…) used during the process needs to be boiled for 5 -10 minutes before using to sterilize.
  • Natto is supposed to be fairly odorous during the fermentation process, so be sure to isolate it.
  • If you use Natto Powder to ferment the soybeans, make sure you use the special spoon coming along with the package.


  • 4 cups of soybeans
  • 2 teaspoons water (boil for about 10 minutes to sterilize)
  • 1 spoonful of Nattomoto Powder or substitute 1 package of strore-bought Natto.
How to make natto

A package of store-bought natto can be used as an alternative of Nattomoto powder


  • A non-reactive pot
  • 3-4 oven-proof glass containers
  • 2 spoons
  • A film of food wrap


Step 1: Soak The Beans

  • After washing the soybeans carefully, you put it in a sterilized pot, pouring water to submerge all of the beans. One tip is that we use 1 part of soybeans to 3 part of water because the beans will triple after soaking for 9 to 12 hours.

    homemade natto

    The very first step is to soak the beans

Step 2: Cook The Beans And Prepare Starter Culture

  • Drain the soybeans from water, now there are 2 choices to cook the beans. The first choice is that you place the beans into a sterilized pot and boil for around 9 hours. But we highly recommend the second option which is much easier and more time-saving. In this case, you need to have a pressure cooker which you can use to steam the soybeans under 15 psi for 40 minutes. (Remember we just steam the soybeans not boiling it)

    where to buy natto

    Using a pressure cooker to steam the soybeans is much more time-saving and convenient.

  • While waiting for the soybeans, we can prepare the natto spore solution by dissolving one spoonful of natto spore into 2 teaspoons of sterilized water (remember to use the special spoon). Another option is to use a package of store-bought Natto as a starter culture for fermenting.
  • After 40 minutes, you can take the soybeans out of the pressure cooker and put it in a large sterilized container. If you cook the beans properly, you can easily break it with your finger. You have to pour the Natto spore solution while the beans are still warm and stir the mixture well. In case you choose to use ready-made natto instead, you can divide it into small amount then mix it together. After this step, you have to make sure that every single bean has natto bacteria on it.

    How to make natto

    The soybeans after 40-minute steaming in the pressure cooker

Step 3: Fermenting The Beans

  • Put a thin layer of beans in 3-4 glass containers. Now it’s time to use the food wrap. The first wrap is put directly on top of the beans, it will prevent soybeans from drying. The second wrap is clung on the edge of the container like an air pocket keeping moisture. Make sure to poke holes both of the wrap because bacteria need oxygen for fermentation.

At this point, place the covered containers in the oven and set the temperature steady at 100°F. The fermentation process will take up to 22- 24 hours.

 japanese fermented soybeans

Natto after taking out from the oven

Step 4: Cooling Down The Natto And Enjoy It

  • Now is the last step before you can enjoy this delicious home-made natto. Remove all the food wraps then let it cool down for a few hours, after that you have to store it for at least overnight in the refrigerator. You can totally look forward to a Japanese-style breakfast on the next morning. Anyone who tries this dish for the first time can take a look at our previous blog What does Natto taste like? to make sure you make the right one.

3. Health Benefits Of Natto

You may know the fact that soybeans can be the source of many health problems. But Natto is different. Although it is made from soy, the fermentation process has removed all the disadvantages of eating raw soybeans. You can be surprised at the health benefits it brings.

  • Weight management: For many women who want to maintain a stable weight, natto is the best choice for you. It is high in fiber, which makes you feel less hungry and promote the digestive system to work more effectively. Besides, it is a low calories dish, so you can control the calo you take in.
  • Preventing heart problems: A special enzyme called nattokinase in natto has been discovered to help lower the chance of forming blood clots in your vessels. It mimics the function of plasmin, a natural enzyme in our body. Plasmin counteracts fibrin which is the main cause of blood clots.
  • Promoting bone health: Through the fermentation process, Vitamin K2 is produced. This vitamin plays an important role in creating healthy bones. Because it helps produce a special protein working as glue to incorporate calcium in our bones.

4. Different Ways To Enjoy Natto

what does natto taste like

A typical Japanese breakfast: fermented soybeans, rice and green onion

         SEE MORE:

So now you know how to make Natto but do you know how to enjoy it. Most people just use fermented beans as a supplement food with rice and soy sauce for breakfast. But you can find more great combination here. We know most of you is struggling for the first time eating this unique cuisine. It doesn’t have an appealing appearance nor smells good. If you have tried the plain natto and don’t like its flavor, there are still many ways to improve its taste. You can mix it with many other foods but these options are the most highly recommend: organic soy sauce, yellow mustard, mayonnaise, or green onion. If it still isn’t enough for you, you can use natto as an ingredient for other food like spaghetti, curry or even soup. The flavor of other ingredients will modify the flavor and the smell of natto and make it easier to eat.

homemade natto

Look how delicious this spaghetti with natto is

Want to know how to make natto in a more detailed way? Check out the video below:

About Haruto Suzuki

Haruto Suzuki is a senior food and drinks blogger at Question Japan. He has a background in F&B industry and also experience of running his own Japanese restaurant in Tokyo for over 10 years. Therefore, he has a great knowledge of Japanese cuisine. So if you want to discover Japan through its unique traditional cuisine, Haruto Suzuki’s blog will be a great source of information for you.