Natto, where to begin? First off, it’s delicious; although, it’s not for everyone. I believe Natto to be an amazing mushroom treat that I can’t get enough of while my girlfriend thinks it is a disgusting abomination that smells like stinky feet and the slimy strings look like snot. My guess is that its an acquired taste and I’m just going to leave it at that.
To make it, you’ll need a few things. A Pressure cooker and a yogurt maker (or an Insta-pot) and a culture starter. You can find a culture starter on Amazon or get some ready-made natto packets at your local Asian grocery store. If you don’t have a yogurt maker you can use a heating pad or an oven on a low setting with the door ajar. They will be in the frozen food section in little styrofoam packets. I paid $3 for a 3-pack. Put one in the fridge to thaw and save the rest in the freezer for another batch.
Take a cup of dry soybeans and rinse them until all the soapy film goes away. Then soak them in a mason jar with filtered water overnight. They should double or triple in size. Discard any beans that float and then rinse them again to remove skins and any more soapiness that you see. This step might take a while.
Next, you will fill your pressure cooker with water up to the canning rack. Then put the beans in a temperature-proof bowl on top of the rack along with a spoon that you will use to mix the starter in. This will ensure that everything is nice and sterile. I use a 15 psi ball on top and put the heat on high. When the steamer starts to hiss I know it is up to temperature and set a timer for 45 minutes. After which, kill the heat, pull off the psi ball and let it rest for at least a half hour before moving on to the next step.
I have found that the pressure cooker is a necessary step. I have tried boiling them for a really long time in the past and they never seem to get nearly as soft as I like them.
While your natto is cooling you’ll want to sanitize your yogurt maker. I use star san because I am a brewer and a few drops go a long way, but If you don’t have any on hand, you can use rubbing alcohol to wipe the inside and sanitize a washcloth.
After your pressure cooker has cooled, go ahead and take the lid off. Pull the starter natto out of the fridge and set aside any condiments that might have come with it. Pull the plastic off the top of the beans and mix them with the spoon that you put in your pressure cooker. Be careful not to contaminate your natto after you already have it pasteurized. Mix the starter until it is slimy and stringy. Then add it to your cooked beans mixing it until a little of the slime covers all the new beans.
Fold the washcloth that you used for sanitizing and use it as a mat between the natto bowl and the yogurt maker. This will help it from becoming too hot. Ideally, you are aiming for a temperature of 100 degrees. It can stand up to 110, but I’ve found some off flavors from the higher temperatures. Now that the hard part is over you just wait 24-36 hours. during which you can open it up once or twice to see its progress. Doing so will let in a little oxygen that it needs to grow, but too much can contaminate it. I have never had any problems with contamination (with natto), but I imagine they would be the same as any mushroom/cannabis grower deals with like cobweb fungus, black, pink, yellow molds, etc.
After the fermentation, you should see a nice wrinkly film over all the beans. This means it was a success, but you’re not done. You then need to cover it with plastic wrap and put it in the refrigerator for another day or two. Then you’re done. Don’t forget to set some aside in the freezer for your next starter.
How you enjoy it is up to you. I like it plain as is. Sometimes I like some soy sauce and hot mustard or horseradish. Before I went vegan I used to enjoy it as Natto Gohan which is hot rice with natto and a raw locally farmed egg. …So freakin’ good!
Medicinally natto is known for an enzyme it produces called Nattokinase which is known for its anticoagulant properties making it a natural blood thinner. The Bacillus classification simply means that it is rod-shaped under a microscope. It’s gram positive, which means it will retain a violet dye. Yadda, yadda, yadda. Click here if you want to learn more about natto.