Mitoku Traditional Natto Spores


Make real Japanese natto at home! Ferment soy beans with these spores to make traditional natto, or use nearly any bean of your choice.

Natto spores (natto-moto) are the starter culture used with soybeans to make traditional Japanese natto fresh at home.

  • Contains 0.1 oz (2.83 g) tube.
  • This powdered starter culture comes complete with a special measuring spoon.
  • Sufficient to inoculate approximately 50 pounds of soybeans to make approximately 88 pounds of fresh natto. 
  • The fermentation process requires the natto be kept at approximately 100°F degrees for 22 to 24 hours.
  • Additional instructions included. 


  • Japanese natural powdered natto starter spores (bacillus subtilis natto).

Allergen Information

  • Manufactured and packaged in a sterile laboratory.

Shelf life and Storage

  • The natto spores will last 6 months in the refrigerator or freezer; 3 to 4 weeks at room temperature.

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Customer Reviews

Based on 53 reviews
Natto Spores

We haven't even opened the package yet...still busy building the house.

Great quality natto starter

I have been making natto using this Japanese natto starter. It works fine with every batch. And this tiny bottle of starter lasts a long time. Will buy it again when the starter runs out.

1st Time & Success to Boot

As one previous reviewer had mentioned, I am lax on OCD sterilizing. (That said, I do clean the equipment etc and ensure food safety and sanitation)

Cutlures for Health did a good job by adding an instruction sheet in English. Plus the spores came in excellent condition and quality.

I am so happy that I can make Natto at home and use the ingredients I trust. Really adds a fun factor and saves me some money in the process.

Will definitely buy from Cultures for Health again!

I don't worry about sanitizing

These spores work just fine for me without doing all that sanitizing. It's cheap enough that I just sprinkle a whole lot more than what is suggested on and mix in. I use simply washed items that have been stored in my drawers and it still works fine so if all the sanitizing in the instructions is too much for you (like it was for me) you can get away with not doing it (at least I have found so) as long as you use enough spores. I do NOT put the spores in water though like in the instructions as that doesn't work. I just sprinkle on top and mix in and then put the containers in my excalibur dehydrator and it works just fine. Also, I don't use sanitized cheese cloth on top. I just wet plain old paper towels. ;)


I was a Newby at making Natto but from first batch on results were great I am getting to like the taste of Natto. I use it most days .