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How to Make Natto

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5 from 9 reviews


Learn how to Make Natto at home three ways with this easy step-by-step recipe!


Units Scale

Natto from scratch (bacteria starter)

Natto from frozen pack

  • 1 pack of frozen natto (or 60g from previous natto)
  • ~380g dry soy beans
  • 1 tbsp filtered water

Natto from previous batch 

  • ~400g cooked soy beans
  • 60g natto from previous batch


  1. Soak the soy beans overnight– it should expand and look plump. 
  2. Discard the water and then cook the soy beans in an instant pot, pressure cooker or over the stove until tender. 
  3. Lay cling wrap on a tray or shallow tupperware (this step is not essential but helps immensely with the clean up process). Sterilize any utensils and bowl with hot water to remove any bacteria. Drain the soybeans well and then add the soy beans to the tupperware.
  4. Add 1 tbsp of filtered water into the pack of natto and mix to loosen. Then spread the natto over the soy beans and mix well. If using the starter, sprinkle the starter over and mix. If using previous batch, add the natto and mix well. Cover with paper towel, cling wrap and then elastic bands to secure.
  5. Place in a yogurt maker, fermentation box or a warm area at 40 C for 24 hours. The next day, place into the fridge and continue to ferment for another 24 hours.
  6. The natto is complete! Store in the fridge for up to 2 days or transfer to portioned size freezer safe reusable bags or tupperware. When ready to eat, thaw in the fridge and enjoy!
  7. You can repeat this process maximum 3 times with previous natto. Then you must use the frozen store bought natto (because the bacteria is stronger). 


  • Prep Time: 15 minutes
  • Cook Time: 30 minutes
  • Category: basics
  • Method: fermenting
  • Cuisine: japanese


  • Serving Size: 1 serving (60g)
  • Calories: 120