OK all you natto lovers out there. Time to resurrect this thread. I’m a self proclaimed nattophile. In fact I make my own by the gallon on a bimonthly basis. It’s very simple to do actually. I can’t seem to find the best recipe/instructions on the internet, so I’ll post my own recipe. I’ve done a lot of trial and error and think I have a pretty failsafe method.
Here’s how I do it:
Before starting you need to keep everything nearby very clean, we don’t want to introduce any foreign bacteria to the mix. Bleach or boil every utensil that may touch your beans.
1. Buy a couple packages of Styrofoamed natto. Actually I bought 5 or 6 different kinds from Chicago Food Corp 3333 W. Kimball. I taste tested them and picked my favorite. They’re always in the frozen section.
2. Then you pressure steam (or steam) the soybeans. I use pressure steaming because that takes 1 hour vs. 6 or more hours. Steaming is only important for flavor, you may boil them and the natto will ferment, but you may lose some beany taste. It’s important to let the beans get soft enough to smash easily between your fingers. Don’t worry about going too soft, the texture firms up a bit when they cool. They need to be soft so the bacteria can travel to the inner bean. Mmm.. bacteria..
3. Let your beans cool just a little, they don’t have to cool all the way because natto bacillus is very strong and can live through near boiling temps. Then you add a couple packages to your natto that you bought frozen. I’d say I use one Styrofoam pack per 4 cups of dry beans. It’s important also not to use too many already fermented beans as the bacteria will breed too fast and kill each other (I think this is what happens). I’m not sure that is exactly how or why but I’ve screwed it up a couple of times by adding too many. So err on the side of less if you’re not sure. You’ll know if your natto is screwed up, it will smell sour. If it smells like natto, or like natto with a little ammonia then it’s fine. (we’ll get to the ammonia smell later)
4. Ok so you’ve mixed it well. Now cover it with something that lets air in (foil or plastic wrap with holes poked into it). Now put the container in a warm place for roughly 24 to 48 hours. I put mine in the oven with a food dehydrator element that regulates the temp to around 98 degrees. You don’t have to be as exact. You can use a light bulb in the oven or keep it on a very low temp (if your oven goes down to 100 that would be good). With my oven between 98 and 103 it only takes 24 hours for my natto to come out perfectly sticky and stinky.
5. Now that It’s all gooey it may smell somewhat like ammonia. This is normal I usually keep it in the fridge for a week after I make it to let the flavors settle in and the ammonia to evaporate. I repeat, if it smells sour, something went wrong. The sour smell is obviously bad if you’re unsure, it’s probably just ammonia and you need to wait it out. After the natto has sat for a week or 2 in your fridge you can bag it into single or weekly serving sizes and freeze them. The bacteria survives the freezer so don’t worry.
Now, if anyone has any suggestions as to what they put in the soysauce packets that come with prepackaged natto, or where to get that mustard, let me know! I’m pretty sure the soy sauce packet has some kind of dashi mixed in, but I can never get it to taste so flavorful. The mustard is something like a mix between spicy mustard and regular yellow. But I can’t seem to find the right brand anywhere either.
Not sure if this thread belongs here on the natto thread or in the recipe section. Mods, feel free to move it, or duplicate it if need be.