Natto: Make-It-Yourself Recipe


Vegans and Vegetarians (and omnivores!) rejoice! Here is a simple way to make your own natto!
It does require a little sneaky trick for the first batch (like for yoghurt) but from the second batch it will all yours and only yours!
As usual, as this is a basic recipe, I willl explain step by step, and mentioning the quantities on the way!

Firts the soy beans (daizu/大豆 in Japanese).
Use a large vessel as you will need 2 to 3 times as much water: 1 volume of soy beans + 2~3 volumes of water.
Make an effort touse clean cold water!
Let the the soy beans soak overnight.

You will discover that after a night of soaking the soy beans will have changes in shape from round to elongated!

Next you must steam the soy beans (preferably the slow way) for three hours to get them soft, otherwise they will not ferment. You may use a pressure cooker, but you will have to expperiment!

Important point: From now on, especially, make sure that all vessels and utensils you use are properly boiled in hot water first to kill all germs, or you will end with a yeast/germ/mold battlefield!
Use a large metal shallow vessel for even wieght and spread.
Transfer the steamed soybeans on eat as shown in above picture.
Be aware that the smell will be strong, so choose your room!

Now, for the all-important “sneaky” trick!
The beauty of it is that from the second batch you will use your own batto! Friends with some knowledge in yoghurt or Japanese sake fermentation will easily understand!
Drop a few grains of natto bought at the market in half a cup of water/ 100~cc/ml. (use high quality non-gaseous mineral water!)
After stirring 2 or 3 times, the water should start turning whitish. This is your yeast/fermentation starter!

Carefully pour the fermentation starter (with the natto beans) evenly all over the steamed soy beans.

Cover/wrap the whole with cellophane paper. Punch small holes (about 20) with a toothpick to allow ventilation.

Tap the cellophane paper so as to keep it close in contact with the soybeans. Do not press.

Now, the whole important thing: the temperature!
Like for Japanese Rice fermentation, it must stay between 30 and 40 degrees Celsius. There are many ways to do it if you do not have the right room for it: use a hot water bottle (above) put nearby and cover it with a blanket, or put it under a heated blanket….

keep checking the temperature!

Let ferment for 20 hours.
Upon lifting the cellophane paper, the natto should show white filaments.

Here is the finished product!
True to tell, home-made natto might not as “sticky” as natto bought in markets, but this is still true natto.
Actually, the lack of “stickiness” might be be a blessing for some!

Keep in mind this is a true food, especially for vegans and vegetarians who are in more need of nutrients than omnivores!

40 thoughts on “Natto: Make-It-Yourself Recipe”

    1. Yeast are not tiny animals they are fungal. And natto is made by Bacillus subtillis which is a gram positive rod shaped bacterium. Is a little creature that can swim and stuff but is not classed in kingdom animalia. You have to eat to live, other living things have to die for you to live. And if you starve to death you are being incredibly cruel to an animal – you!


      1. That is the “interesting” part about being a vegetarian or even vegan. They are declaring the “kingdom animalia class” as beings which shouldn’t be eaten and declare all other living things as “it’s okay to kill and eat them”. On a side note: Even plants are alive and do feel what happens around them.

        I believe it’s best not to declare something as “not okay to eat” just because we can relate more easily to these creatures.

        As an omnivore, we have the power to treat all living things evenly and can “eat all of them”. We can still be picky about food and chose what we eat, but that should be based on likes and dislikes, rather than some strange, warped, superficial things most (not all) vegetarian/vegan people have.


  1. Hi I have purchased the
    Kinetic Culture” from Dr mercolas website. It has the right bacteria for making the Vitamin K2 which is what natto has. I was wondering about trying to use the powder on organic chick peas ! What do you think?
    kind regards


  2. Hi! Well, I hit a wall using my “3rd” or possibly ‘4th” generation natto from my own batches. This batch has very few strings. I will travel to get the frozen import, and use that for my next batch. However, a question: even if it’s not stringy, is there still a good amount of nutrients (specifically vitamin k2, MK7) in the batch to make it worthwhile eating? I’m using this food as a part of my overall health plan, and the MK7 is the main reason I started this natto-making project (besides the fact that I love this stuff!) I can’t find anything specific on the ‘net, perhaps you know! Thanks!


  3. Hi,

    I am planning to prepare some Natto this weekend. But I am having difficulties in finding the Natto-kin starter / culture. I know I could use the 2nd batch Natto as a starter but how can I make the first bacth when I dont have the culture available here in my city(Bangalore, India)

    Is it possible to prepare Natto without the bacteria culture at all? May be by allowing it to sit for more than 48 hours soaked in water or something? How to about curd bacteria? Please let me know an alternate solution to this and something that is possible in India.

    Also I have always wondered as to how I could be sure that the end result is nutritious though it is stinky and NOT some rotten food which is filled with bad bacteria? Is there a defiite way to difefrentiate the good and the bad?

    Liked by 1 person

    1. It is like cheese *I should know, I&m French! LOL), all fermented foods have a strong smell!
      You cannot prepare the Natto without the bacteria, full stop.
      The Japanese use the environmental bacteria inside their factories whose walls and ceiling they never wash!
      So, as you said you might have to come back regularly to imported natto for more batches. Make hose batches bigger as they can be frozen!


  4. Hi
    Great article thank you. Do you know where you can source the starter culture for the Natto Please. I live in Mandurah , western Australia.

    Liked by 1 person

      1. Thank you
        If I use a commercial bought Natto ( I cannot find any organic Natto) to make the starter and use organic soy beans, will the new Natto then have GMO contents from the original Natto ? I have been wanting to make only organic non GMO Natto.
        Kind regards


      2. Hi there
        I just attempted to ferment my first batch !. Still some liquid ! Did I use too much ? Cant see white filaments :-( Is it fermented? is it safe to eat. How do I store it ?
        Kind regards


    1. Hi there
      I just attempted to ferment my first batch !. Still some liquid ! Did I use too much ? Cant see white filaments :-( Is it fermented? is it safe to eat. How do I store it ?
      Kind regards


  5. thanks for the information! I’ve had major success with my natto batches recently, they are so stringy it’s amazing. Tastes wonderful. I make a new batch about every 3 weeks, using leftover starter from my previous batch. Glad I found the information on your website!


  6. For msbeastle

    organic works for me but ordinary don’t. If you’re getting white mould, it’s working. If your beans are soft enough, then you may need to ferment a little longer to get the strings. If the beans aren’t soft enough, it takes a very long time for them to ferment and/or they don’t ferment properly. I soak mine for 18hours and steam in a pressure cooker for 1hour. works for white and black soy. I’ve used Japanese natto starter but using bought natto as a starter has worked really well too


  7. Ah, I wish it were so…I stirred and stirred, and not a thread appeared. I think the beans were not soft enough after pressure cooking. I already have my next batch soaking. I’ll change up a few things and maybe the next batch will be better. *sigh*


  8. Thanks for your quick reply!
    Please allow me to clarify: if I make a large amount of beans, but do not use them all at once to make natto, say I use only half of them – the extra beans NOT mixed with the natto starter, just soaked and steamed – if I freeze these BEFORE mixing with natto starter, and use them some time in the future, (defrost, heat up, mix with natto starter, ferment) will that be OK? Thanks for your patience!


    1. Dear Jackie!
      No, actually, you have to make the whole natto first and freeze it all. Frozen cooked beans will not work well because of the water inside the beans breaking the texture!
      best regards,


  9. If I make a large amount of beans, but don’t want to use all of them for a batch of natto, can I freeze them? Then when ready, defrost, heat them up and then add natto starter and make a batch to ferment? I’m planning on using a natto maker machine, which only holds 1 liter (about 1 quart). It’s a lot of work and time to process the beans to get them to the point of adding natto starter, so I thought freezing the excess and using them later might work. What is your opinion?

    Also, OK to substitute regular black beans or garbanzo beans instead of soy beans? Thanks!


    1. Dear Jackie!
      Freezing natto is no problem. Make sure the packagng is as airtight as possible.
      I’m afraid only soy beans can be made into real natto, but you never know. It all depends on taste, texture, etc.!


      1. Just completed my first batch of “not quite” natto. Tastes good, but strings are so few as to be nonexistent. Not sure where I went wrong. Followed all steps, saw white stuff growing on the beans in the incubator, but no “neba neba” to be found.
        Even bought the smaller, round, organic non GMO beans! Used starter culture from Gem Cultures (no local Asian market for 1.5 hour radius), sterilized everything, had a constant 107 degrees incubator…
        any suggestions?

        Liked by 1 person

  10. I used to eat this food from time to time when I was on the JET programme as an ALT in Japan. Since coming back to Australia & reading some negative things about soy foods (in relation to women who have PCOS) I cut all soy foods from my diet. However I have just read an article by a very credible source on natto being the highest known food in vitamin K2, known as the ‘anti-wrinkle’ vitamin. The fermentation process reduces the phytic acid content of the beans & does something magic to the proteins & amino acids basically unlocking the nutritional potential of the beans. Ancient China & Japan can’t be wrong… & look at the beautiful skin many people have there! There is a world of difference between the processed foods & oils that have become ubiquitous in the modern diet & are derived from gmo soybeans & natto made from the non gmo organic Australian grown soybeans I have just bought. I plan to give this a go & have acquired some frozen imported natto to get started (thanks for the thawing info above). I have been making my own kombucha & keffir for a while now so I thought I’d be able to innoculate a batch with a starter from a commercially bought product.
    One detail I wanted to ask about: do the beans really have to be laid out singularly like in your photo. I ask because I was hoping or thinking I could resuse the polystyrene containers that the store bought natto came in as well as the cellophane sheets that lie on top (of course they will be squeeky clean). Do you think that will work?


  11. Here in Australia, cellophane is a gift wrapping paper….could you mean cling wrap (elastic like plastic that stretches)


  12. A great and very important recipe for me, i need to ferment soy beans to make them healthy otherwise they are not. But i have a few questions:

    “Carefully pour the fermentation starter (with the natto beans) evenly all over the steamed soy beans.”

    Do the soy beans need to lay in this fermentation starter water? or hardly need to be touched by the water? i dont toss down the fermentation starter water right? but does the water surface need to be as high as the soy beans in the vessel?
    Many thanks for this article.


    1. Dear Dennis!
      You are most welcome!
      “does the water surface need to be as high as the soy beans “: Yes!
      Don’t hesitate if you need more information!
      Best regards,


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