Last week it was nata, this week it’s natto. Though both are delicious (and maybe a little challenging by some standards) they are not otherwise easy to confuse. Nata is candy made from a kombucha, jun or vinegar SCOBY. Natto is an alkaline, Japanese, soy ferment that has had me smitten ever since I first read about its health benefits in (say it with me) The Art of Fermentation by Sandor Katz.
I had never tried natto before reading The Art of Fermentation, and after reading about it both there and elsewhere, I was intimidated. Descriptors given both in my reading and conversation with Japan-dwelling friends: slimy, mucilaginous, disgusting, okay when you eat it with a ton of mustard, not for non-Japanese, bizarre, gross, funky, stinky and unpleasant. That’s the short list. With those ringing recommendations, it somehow kept getting pushed down in the rankings on the to-do list of my experiments. When I finally tried some in a restaurant and, later, others from the freezer section of my local Japanese market, I felt something between disappointment and confusion. I was a little disappointed that natto wasn’t a bit more challenging and I was confused that everyone and their mother had described this food as slimy.
Natto Texture
I hate slimy. A lifetime battle with mushroom hatred and an inability to swallow certain items from certain regional foods has taught me that sliminess is my food dislike. Natto is not slimy. If anything, it’s the opposite. Its changing web of strings and strands are on the sticky side. And I love them. My first through fifteenth bites of natto reminded me of a very toned down version of that time in the Peruvian rainforest when we snagged a few fruits from the latex tree. As you might imagine, fruit from the latex tree has some interesting qualities, the main one being that your lips stick together for hours after you eat it, with no relief available from soap or water scrubs (the ambrosial flavor makes it worth eating anyway). This is a way more exaggerated effect than the bit of cling you get from eating natto, but it was certainly a closer reference for me than anything mucilaginous that may have crossed my plate in the past.
Natto Taste
The flavor is a little bit roasty, a little bit funky (think blue cheese) and a lot soy. For me, this is a wonderful thing. Like many others, I gave up unfermented soy under duress. I hit a pretty rough hormonal period (sorry, gents) and after an elimination diet, I learned that soy was the culprit for me. As a long-time tofu lover, I was pretty distressed. But a crying-for-no-reason-fit in the middle of the street, and a few horrible bouts of cramps convinced me that the sacrifice was worth it. Two years later, I’m my (arguably) sweet self all month long. But I do periodically get the strong desire to whip up a batch of super firm tofu and while natto doesn’t have a whole lot in common with tofu, the leguminous flavor does tame my soy-seeking beast.
Natto Health Benefits
Natto is special for another reason: those health benefits I mentioned above. While most fermented foods become alkaline during the fermentation process due to increased mineral bioavailability, natto is actually just an alkaline food due to its key fermenting bacteria Bacillus Subtilis Natto. (More information on that in The Art of Fermentation by Sandor Katz, pg. 329). Better yet, an enzyme is produced during fermentation that is both clinically proven to do amazing tricks and suspected of having a few others up its sleeve. Most importantly, this enzyme, nattokinase, has been shown to do in plaques in the arteries and is suspected of having a similar effect on plaques in the brain (aka those bastards who cause all kinds of neurological disorders like the plague of alzheimer’s). It is also used to tread tons of conditions, from heart disease and hemorrhoids to varicose veins and infertility. The many healthy properties are what had me sold, initially. With a strong desire to avoid all aforementioned plaques, this miracle food sounded pretty good to me. Now that I eat it regularly, I dig it for the flavor.
Why Make Natto?
I make natto for the same reasons I make most things: it can be hard to find organic natto and I’m not a fan of GMO soy. And, of course, homemade just tastes better. Homemade natto is simultaneously funkier than commercial and definitely more intensely umami (think red meat or blue cheese). We’ve been using it all kinds of places that break with tradition, including seasoning with barbecue sauce and making “natto pâté.” The soybeans I use tend to be larger than the soybeans I’ve had in commercial and restaurant nattos, so if you were/are a regular consumer of commercially produced natto, do be prepared for that difference.
NATTO RECIPE
Although there is some equipment needed for this process, if you can make yogurt, you can make natto. There are a couple things to consider, though: the amount of spore needed is TINY, so the quantity of beans you need to make is enormous (1 kilo of dried beans!). You need to be able to maintain a warmer temperature (~103F) for 24 hours. I do this with a heating pad with no off switch inside my oven. My experiments with culturing in jars did not go well, so I don’t think your typical yogurt maker is a good option here.
I bought my natto spores from Cultures for Health. The instructions included with the spores were good, but very focused on sterilizing everything in sight. I use my normal standards for fermenting when making natto, which for me means a very clean kitchen, clean implements, vessels and pots and no sterilizing.
Equipment
- shallow dishes sufficient to hold 1 kg of soybeans after they’re hydrated and cooked (I used my pyrex 4.8 quart baking dish, my 8-inch square pyrex dish and my
- plastic wrap or aluminum foil (sadly, I’ve found that plastic wrap works best for natto in my home)
- a large pot
- a heating pad with no off switch or another device or process for maintaining a 104 degree temperature for 24 hours straight*
- kitchen thermometer
- a very large bowl, such as one you might use for sauerkraut production
- a kitchen scale (optional)
Ingredients
- 1 kilogram (2.2 lbs) dried, organic soy beans (seriously, buy organic, or you’re definitely getting GMO soy)
- 0.1 grams natto starting spore (bacillus subtilis natto)
Process
- Rinse soy beans and remove stones and unwanted beans
- Place beans in a large container and add at least twice as much water as there are beans
- Soak for 12 hours. Once the soaking period is over, drain the beans and place them in a very large pot. Cover with water and bring to a low boil. Allow to boil for 5-6 hours or until beans break apart easily but are not yet mush.
- Strain the beans. Allow them to cool slightly, for about 30 minutes. While the beans are cooling, bring a 1/2 cup of water to a boil and allow it boil vigorously for 5 minutes. Remove from heat and let it sit to cool for 10 minutes.
- Add your tiny, tiny spoonful of natto-moto spores to the water and stir vigorously until the spore powder is dissolved.
- Pour spore liquid over your cooked beans and stir very thoroughly to distribute the spores as evenly as possible. I spend a good chunk of time stirring.
- Transfer inoculated beans to their culturing containers. I use my pyrex baking dishes (think lasagna, not loaf). You don’t want the sides very high and you don’t want the beans to be layered too deeply. 1-2 inches deep should do it. Cover containers with plastic wrap and place them on the heating pad in the oven, or use whatever contraption you use for incubation.*
- Wait 24 hours. Remove plastic wrap and stir beans. You should see the characteristic natto strings. The beans on the surface may look a tad cooked or wrinkled. It’s nothing to worry about. Stir the beans to integrate the guys who were on the top. You can eat your natto after a couple hours in the fridge or store them in the fridge for a week. I put half in the freezer as soon as it’s cooled. These quantities are not consumable by my family of two, and the freezer maintains their fun strands.
*There are many ways that one can do this. If you do it my way, use a kitchen thermometer to measure the temperature of the various heat settings on your heating pad before you start this process. Keeping it between 100F and 110F has worked best for me.
Priya says
Yesssss! I’ve been waiting for this post! I have fibromyalgia and have thought about taking a nattokinase supplement, but it’s really expensive and I’m more of a food-as-nutrition kind of gal. I actually give my cat a nattokinase supplement to reduce strain on his heart, at the advice of our holistic vet (he has a murmur). Natto here we come!
Amanda says
That’s awesome, Priya! I’m so glad to hear it. I’d love to hear if you find it uber funky. I was honestly shocked at how not challenging it was when I first tasted it. To be fair, I eat ferments from around the world as a regular part of my diet, so maybe my weirdness tolerance is high. 🙂
Priya says
I like challenging and funky foods, so I am ready! Just gotta get the culture. Do you happen to know of any shops in Philly who sell the culture (preferably in smaller portions)? I’m going to be in Philly just about every weekend in May (vending at craft markets!), and it’d be awesome to avoid buying a crazy amount of culture and paying for shipping. 🙂
Ann says
This is one my my favorite foods. It took me 6-8 years of trying natto 1-2 times a year to develop a taste for it. Now I really do love it. The gooey,sticky, stringiness of it has never bothered me (I’m a good little Southern girl who loves her stewed okra), but the taste and smell is what took time for me to appreciate. My kids, on the other hand, have loved it almost from the start. All 3 of them, ages 2, 7, & 10, ask for it often. I think one factor to them wanting to like it was this video on youtube: http://www.youtube.com/watch?v=Zn5vrhIUAMY .
I have started making it myself using beans that are not soy. My most recent is with pintos. I just use part of a package of frozen natto as my starter. It turns out great. What I miss, though, is the seasoning packets. We usually shake a little fish sauce, soy sauce, and/or mustard on it.I think about slicing up a scallion to add in there, but my laziness takes over and I don’t actually do it.
My advice for others who are first trying it – If at first you don’t like it, try, try, and try it again and again and again. You will eventually like it! (especially if you use the seasoning packets that come in the frozen natto!)
Amanda says
Haha, Ann! Nice video.
Did you get the strings with pintos? I tried a couple other kinds of beans that were definitely fermented, but not particularly stringy. It’s a deal breaker for me! I love the strings.
Drew says
Oh this is great news for me! I live in Australia and I cannot find the spores anywhere, not even from Cultures for Health’s Australian affiliates. Disappointment! I will begin looking for frozen Natto asap, thanks!
Amanda says
Hi Drew,
You can definitely make natto without spores. It will take a bit longer to ferment, but bacillus subtilis is naturally present on the beans and is very heat tolerant, so cooking won’t kill it!
Nattonut says
Not “naturally present” on the bean.
Naturally present in rice bran.
Amanda says
Hi Anna,
There is no rice bran in natto. Just soy beans and bacterial culture. Some people put it in a bit of flour (rice or wheat) to distribute it more evenly over the beans, but even flour isn’t a necessary ingredient, so I’m guessing you’re thinking of another food that does include rice bran.
Julia says
I purchased mine from a Japanese seller on ebay recently. Total cost was 25 aud
Jungle Jeff says
Anna, great to hear I can use reserved Natto to re-inoculate the next batch w/o having to continually buy the starter grains. How much Natto do you add, in proportion to freshly cooked beans?
Do you know if this also works for Tempeh?
Ann says
They do have the strings. My heart and stomach did little happy excited flips when I stirred them up and saw the strings. Makes me laugh at how excited I get about it. They don’t get as foamy-stringy as regular natto when I do a big mix of them, but the strings are there. I have always used a package of natto for my starter, though. Maybe that makes the difference. I have never tried using just the spores themselves. If they didn’t get the strings I wouldn’t be as excited about them either. Hmm… That makes me a little bit hesitant to order spores. I’ve been contemplating ordering a package of natto spore and a bag of brown rice koji so I can make some non-soy miso. I’ll need to thinkbaout this, because if you, oh fermentation fab master that you are, don’t get strings with non-soy beans, I know I wouldn’t get them.
Just read your most recent post. I am a very deep shade of green with envy that you have a restaurant you can go to that serves ferments. One of my cousins lives up there in Philly. I’m going to have to start talking to him more than once a year so that I can go visit up there with a free place to stay. You really make it sound like a wonderful place!
Facebook says
Hey! I could have sworn I’ve been to this blog before but after reading through some of the post I realized
it’s new to me. Anyhow, I’m definitely happy I found it
and I’ll be bookmarking and checking back frequently!
Letha Hadady says
Thanks for this blog Amanda and your enthusiasm for Natto. I would like to make it without adding natto spores and using non GMO soybeans. How long do you have to ferment the cooked beans without the spores? Can I put them into a jar in a closet or does it have to be in an oven? I have read that the heat should be a constant 100 degrees for fermentation. My oven does not go that low. I don’t want to use natto spores from Japan because of radiation.
Amanda says
Hi Letha,
The beans definitely need to be cultured in the range of 100 degrees (104 is ideal). They need to hold at that temperature for quite a while, and they need to be in a flat layer, so in a jar is definitely not a good idea.
Some ideas for you: test the temperature of your slow cooker, test the temperature of your oven with the oven light on, fill a cooler with 104 degree water and check them frequently to make sure the temp has been maintained (add more hot water if not). There are lots of ways to get the right temperature, but it is an essential element for natto fermentation. The bacteria will simply not culture if the temperature is too high or too low.
Good luck!
Tal says
Hello Amanda,
The instructions with the Nattomoto and also another website for making natto http://www.macrobiotic.org/natto.htm
Specify 500 gr soybeans with 0.1 gr natto spores.
You’ve posted double the soy beans per same amount of spores. Can you please clarify the difference? Thanks!
Gloria says
I am excited to find a recipe for making natto because after the radiation complication I have no longer bought it. HOWEVER: how can COOKED beans be fermented? I thought fermentation requires enzymes? Thanks for clarifying. Gloria
Amanda says
Hi Gloria,
A couple things: first, you’re inoculating with a spore in the recipe I’ve used here (although some do it without). Second, This is not lactofermentation. The bacterium responsible for natto fermentation is bacillus subtilis natto, and it is a strain of bacteria that tolerates temperatures way above what your average kraut-fermenting lactobacillus will.
I hope that helps!
Amanda
Alkaline foods Recipes says
WOW just what I was searching for. Came here by searching for nattokinase
Anita says
Sometimes I use the spores as starters, sometimes packaged Natto. Easy to make once you get the hang of it. http://earthlychow.com/miracle-food-from-japan-easy-homemade-natto
Gill says
There’s a Yahoo Group for natto-makers and one of them experimented with adding glycerine, and it increased the stringiness massively (I think they said 48-inch long strings!) – check out
https://groups.yahoo.com/neo/groups/nattosupport/info
I’ve just ordered some Natto spores myself off ebay and I’m going to have a go; I’ve never tried it before but I like strong blue cheese so it’s worth a try!
Amanda says
Huh! Super cool! Thanks so much for sharing this.
Gloria says
Apparently adding a little brown sugar or molasses to the ferment at the beginning increases the stickiness and bacterial activity greatly. I’m going to add ½ a teaspoon to my next batch of 1 cup dry weight and see what happens. (that’s about 3 cups cooked).
‘They’ tell me the minerals, and instantly available sugars give the ferment a massive leg up, and then it all goes swimmingly from there.
Rebekah says
Hi, can I make tofu out of natty soybeans?
Rebekah says
sorry, *natto
Amanda says
lol. I got it. Gotta love autocorrect.
Amanda says
Hi Rebekah,
It’s worth a try, but the truth is I don’t know if the changes the soybeans undergo in natty fermentation will impact the quality of the milk or the possibility of coagulating it for tofu. Could be a fun project, though! As with all experiments, I would say to keep it small! if it doesn’t work, that limits the loss.
Bernard Carder says
Bernie here : I’ve been making soy natto for over a year, I enjoy eating it. This past week I was careless and let the oven temp go above 124° for 4 hrs. Anyone know if it harmed the ferment process.
Lynette Crawford says
Hi, I have a SoyQuick soy milk maker which I have used in the past to make soy milk, not very successfully. Understanding now, the importance of fermented foods I have been using a commercial fermented soy milk ‘Bonsoy’ which I really like. I’m wondering if it is possible to and how I would make fermented soy milk using my soy milk maker? Regards Lynette
Amanda says
Hi Lynette,
I’m not familiar with either of those devices. If you just want to ferment your soy milk, there are a variety of ways to do it, depending on your intended goal and available temperature controls. You could add yogurt cultures, a little bit of kombucha or milk kefir, juice from an active fermented pickle or sauerkraut, yeast, the contents of a probiotic capsule, etc. The outcomes will vary and only some of those will make it probiotic (if that’s a goal you have). There are endless possibilities!
Dina says
Hello, I purchased a natto powder with great reviews on Amazon and need some instruction on making natto yogurt. I read about someone that uses organic soy milk and that powder and lets it sit 3 days. He didn’t post how much powder or how much milk! The product is Natto Powder by a company named Sagawashoyu on Amazon. It’s all in Japanese so can’t read it on the label.
Amanda says
Hi Dina,
That sounds like a fun experiment, but I have never tried to use that particular soy culture for anything resembling soy yogurt. Very cool idea, though! If you’re using the most common brand of natto starter, the instructions for making natto (not soy yogurt!) require an incredibly tiny amount of culture for a relatively large batch of natto.
I would be very curious to see how this turns out, given natto’s slimy texture. I may have to do some experimentation of my own on this!
Best of luck!
Jeanne says
I’m about to give up on the idea of making natto beans. I bought organic beans, ordered the natto spores, and cheese cloth to cover while fermenting. I thought the bread proof setting on my oven would work perfectly because I use it for fermenting grains and legumes and I thought that setting would keep the natto beans warm enough, but it does not. Without the light it’s only at 85 degrees, and with the light it gets up to 93. Wish I could ferment them in my Instant Pot which has a yogurt setting, but that won’t work because the beans need to ferment in shallow pans. Bacillus Subtilis is an awesome microorganism which resists antibiotics and helps turn bad bacteria into good bacteria, alleviating various health conditions according to German researcher Dr. Dietrich Klinghardt. (Dr. Mercola YouTube). Does anyone know if I can just safely inoculate myself with the tiniest particles of natto spore without the hassle of trying to figure out how to ferment the beans? Some probiotic capsules have it, but I don’t trust their quality.
Amanda says
Hi Jeanne,
Others might choose to weigh in, but IMO, that decision should be yours. I’m sure microbiologists and commercial producers would say that you must use sterile conditions and a single strain bacterium. If you travelled to the parts of Japan from which natto hails, you’d probably still find some folks making it in hay rolls, with no official starter bacteria.
I do have specialized chamber now, but for many years, I made natto as described in this post. I have witnessed it made in conditions that are far from ideal, but still produced delicious natto. I wouldn’t hesitate to try a small batch in the bottom of your instant pot, although those temps could easily get too high for natto production.
Gayle Hardine says
You could try putting a seed mat or a heating pad in you oven on low to make it hotter. But be very careful DON’T FORGET IT AND DON’T LET IT GET WET. It would be a shame to turn on your oven later and melt it. In addition, who knows what electronic horror would happen if you turned on the oven with the heating pad still in there AND it was still turned on!! Hmm, maybe this is really not a good idea on second thought..
I understand the real benefit of eating natto is that it is very high in vitamin K2 (the food with the highest known amount of K2 by weight in the world) for strong teeth, bones and other health benefits because vitamin K2 is very deficient in our world. While Bacillus subtilis natto is in different probiotic formulas my understanding is that taken that way it is to improve the gut microbiome, alleviate dysbiosis, SIBO, the health problems of poor digestion and inflammation of the gut etc. So, as far as just taking the spores straight is concerned I guess it partially depends on what you are trying to accomplish.
Taking it orally you are not necessarily going to get a lot of K2 in your gut unless you’re eating the right pre-biotics for the spores to grow on, and given bowel transit time, I’m betting you would have to continually eat more spores and pre-biotics to keep the ferment going in your intestines to get enough K2. But then maybe that’s just another way people have gotten their K2. I don’t think Western Medicine knows (or cares) enough about this subject to give an answer. Maybe an OMD would know, something or an acupuncturist, but they wouldn’t call it K2 and would have a totally different interpretation of the whole process which would be interesting to find out anyway.
Sharyl says
After I originally commented I appear to have clicked the -Notify me when new comments are added- checkbox and from now on each time a comment is
added I recieve 4 emails with the exact same comment.
Is there a way you can remove me from that service?
Kudos!
Amanda says
Hi Sharyl,
I’m sorry, but that appears to be a user-controlled feature. I can’t see who has subscribed to comments, so there’s no place for me to “undo” it.
Amanda says
Actually, I can delete your comment if you’d like. That might do it.