I love to notice how cultured foods tend to retain their indigenous names even as they travel around the world and find their way into new kitchens far from their land of origin. Reading through a fermentation book is like reading a travel guide, with one exotic-sounding name after the other: kvass, kombucha, kefir, tempeh, kimchi, sauerkraut, labneh, idli, dosa, tongba, miso… or how about gv-no-he-nv? In most cases, when adopting these cultured foods, other cultures have simply kept the original name, no matter how awkward-sounding. Why? Because each name designates a specific, unique strand or type of fermented food. And each name tells a story about where it comes from. Tibetan tara is similar to, but different from, the kefir that originates from the Central Asian Caucasus. Finnish viili is quite unique in comparison with what we call by the Turkish name yogurt. If we were to call all of them “cultured milk,” all those unique flavors and textures would be lost in translation.
So also tempeh — originally from Java, Indonesia — has become a part of both the cultural palate and the vocabulary here in North America. In our (mostly vegetarian) household, we eat it probably at least once every two weeks. But I haven’t ever made it myself before. Reading Sandor Katz rave about how fresh, home-made tempeh tastes so much better than the store-bought kind wrapped in plastic got me curious… And here it is:I think of tempeh-making as having three parts. The first, de-hulling the soybeans, is the most labor-intensive. The second, the actual mixing of the soybeans with the tempeh spores, is super quick and easy. The third part, the incubation, is the trickiest because it requires a very specific temperature range and needs to be closely monitored.
De-hulling the beans is necessary for the tempeh mold to grow properly. It can be done either by cracking the beans in a grain mill, or soaking and then gently rubbing and kneading them until the hulls come off. I did the latter and although it took me a good while (mostly because I was still figuring out how best to do this), I felt that I was getting to really know my soybeans.
Towel-drying the beans after cooking them for an hour felt equally intimate. Then, you simply mix in some vinegar (to acidify them) and the tempeh starter (mine came from Cultures for Health), and pack the entire mix into a large, perforated ziploc bag.
Now comes the interesting part: incubating the tempeh at a tempeh-rature (sorry, I couldn’t resist) of 85-91 F, but ideally even more strictly at 88 F, for roughly 24-48 hours. The proper temperature is critical. I can’t maintain such low temperatures either with my oven or with my food dehydrator, so I turned a plastic cooler into an incubator by placing mason jars filled with warm to hot water in there to maintain the heat, checking the temperature frequently, and removing/adding jars as necessary.For the first day, nothing was happening. I was already about to give up when I noticed the hairy white mold beginning to form in the spaces between the soybeans. Gradually it grew dense enough to hold the beans together as one cohesive loaf. The entire process took almost two and a half days, but at the end of it, I had tempeh. Definitely the high point of Fermentation February so far!