Natto is typically made using soy beans, but seeing as we can’t have that, I’ve tried making it using red beans. I feel that chickpeas (garbanzo beans) might come closer to the texture and feel of soy beans in this application but I figured it couldn’t hurt to try it with red beans.
The recipe calls for steaming the beans first. Pressure steaming greatly speeds up the process so that’s what I did. About 45 minutes at high pressure in my stovetop pressure cooker.
After that, I let it cool to below 40 degC and then added the powdered Natto bacteria culture. After it was thoroughly mixed in, I put the mixture into a shallow Pyrex baking dish, flattened out the beans in the dish and covered it with plastic wrap (touching the beans). The mix goes into the oven, and our Samsung oven is set to the “proof” setting (typically used for proofing wheat-based breads before baking).
This is the mixture after 12 hours overnight.
The above result is after 36 hours. 24 hours was not enough to get the stickyness so I left it in for another overnight period.
The stuff is pretty stinky. I am used to the soy Natto smell but this is quite different. If you know what red bean smells like on its own, you can actually get an idea of what the natto bacteria itself smells like.
On its own, the taste is quite neutral (I.e. not having much of a taste in and of itself) besides a slight bitterness. The texture is essentially like a slimy bean, with a slight grittyness mixed with the slimyness. The red bean texture isn’t as pleasing as a soy texture. Maybe chickpeas is the way to go?
Overall, Growing the natto culture on the red beans was a success, but I think red beans isn’t quite the right bean for Natto.