When I first started making tofu last year, I included a tempeh starter with my first order of tofu coagulants. Unfortunately, although making tofu came naturally to me and I considered the result perfect on the first attempt, I had a lot of trouble when I tried to make tempeh. The first problem is you have to crack and hull the soy beans, a process I found tedious and annoying. Most instructions I’ve found say that after soaking the soy beans for 8 hours, you should rub them, squeezing each one between your thumb and forefinger in order to remove the skin and break the soybean in half. If you do this under water, the skins should float to the top of the container and you can just push them out. Not only did I have problems with the skins magically floating away on their own, but my hand ached after nearly an hour of soybean rubbing. I attempted to incubate the tempeh using a food dehydrator, but despite my best efforts to keep the temperature as close to 88 degrees Fahrenheit as possible, I think it got too hot and the tempeh didn’t look right. I threw it away.
The horrible process of dealing with the soybeans made me shy away from further tempeh attempts, until last weekend when I was looking at my favorite kitchen appliance and I realized I could use the mixie to crack the soy beans when dry. If I didn’t have to rub every individual soy bean, I was willing to try to deal with the hulls again.
So I fitted the mixie with the dry grinder attachment (which is not the attachment shown in the photo) and put some dry soy beans in it …
… and pulsed it several times until most of the soy beans had been cracked.
I was then very happy to find that the hulls actually floated better this time around and I was able to simply float most of them off this time:
After removing as many of the hulls as I could (but not driving myself crazy over removing every last one of them), I drained the water …
… then soaked them overnight. In the morning, I rubbed them a little bit to force any remaining hulls to float up, and skimmed off the few that I found.
Then I drained them again, put them into a pot, covered them with water and a tablespoon of vinegar and cooked them for half an hour. While they were cooking, I prepared a ziploc bag by piercing it all over with a thick needle at 1/2″ intervals, which is probably next to impossible to see in the photo.
After cooking, I drained them a final time and returned them to the pot, where I put them over medium-low heat and stirred for about 5 minutes, to thoroughly dry them. It seems that trying to incubate wet beans is a recipe for disaster. I’ve also seen it suggested to dry them in a towel. Heating in the pot seemed a lot easier.
Next I mixed in the tempeh starter. Tempeh starter is a mold called Rhizopus oligosporus. I purchased it from GEM Cultures, the same people I recommended for tofu coagulants. (And yes, I’ve been eyeing up those miso and soy sauce starters because I’m just crazy enough to make my own miso and soy sauce.) If you are interested in making tempeh, I don’t think there are any easy-to-find substitutes for the tempeh starter, like Epsom salts and vinegar for tofu coagulants. Here’s what the starter looks like:
The amount to use is one teaspoon per pound of dry soybeans. Because I failed the first few times I tried to make tempeh, I started using only 4 ounces of soy beans per attempt, so I used 1/4 teaspoon. This resulted in about the same amount of tempeh found in a commercial package (12 ounces), which is a good amount for Mark and me. I’ll probably use 8 ounces next time and freeze half after it’s made. Anyway, stir the starter in very well to ensure it is equally distributed.
Place the soy beans into the prepared Ziploc bag. You can fit 8 ounces of dry soy beans (after cooking) into each standard-sized Ziploc bag. Lay the bag flat and make sure the soy beans are equally distributed, and that the layer is not thicker than 3/4″.
Your next challenge is to keep the soy beans at about 88 degrees Fahrenheit for about 24 hours. This was something else I struggled with. I thought about leaving them outside yesterday but at 100 degrees, it may actually have been too hot! Plus I wanted to come up with a method I can use no matter the weather. What finally worked for me was putting the soy beans on a wok steamer nestled into a yogurt maker, the lid of which I kept partially on for the first 12 hours then removed. After 12 hours, the tempeh will begin generating its own heat, which you’ll want to compensate for. Here’s my contraption:
When the tempeh is done, it will have congealed together and somewhat disconcertingly be covered in white and black mold:
Here’s a cutaway picture:
My next goal is to think of an alternative to the Ziploc bag. I had to cut it away in order to remove the tempeh without breaking it, so I won’t be able to re-use it as I’d hoped. Although it’s still less packaging than buying tempeh, I’d really like to devise a more Earth-friendly method. I believe banana leaves were traditionally used in Indonesia, from whence tempeh originates, so I may see what kind of leaves I can find at the Asian market.
Incidentally, I read somewhere that although Indonesian tempeh contains the elusive vitamin B-12, pre-packaged Western-made tempeh is too “pure” to contain it (unless it is artificially added). However, the article further stated that people who make homemade tempeh probably end up “contaminating” it enough that it will contain B-12. I’ll have to see if I can back that up, although even if it’s true, you’ll never be able to control the amount of B-12 and should not consider homemade tempeh a reliable source of B-12. You can, however, consider it delicious.