How to Make Tempeh (With Soy-Free Options)

The History of Tempeh

Tempeh got its start in Indonesia, and it’s essentially just tender cooked legumes bound together by a dense mycelium of white Rhizopus mold. It’s suspected that in Java, Indonesia tempeh originated as a byproduct of tofu and soybean oil manufacturing. When food crafters would press oils from nuts and seeds and liquids from soybeans, the resulting waste products were fibrous and dense seed, bean and nut cakes that were to be discarded. This soybean waste is called okara. It’s speculated that the okara got contaminated with fungi used for soy sauce production. Accidentally inoculating okara waste with fungi brought about a protein-packed, fiber-rich food that is quite delicious… and quite economical. So, accident or not, if you love tempeh you can thank Indonesia for this delicious food!

Why Tempeh is FANTASTIC for Gut Health

I think that tempeh is the best way to consume soy and other legumes. The tempeh fermentation process helps to remove phytic acid from legumes making them easier to digest. The elimination of phytic acid through the fermentation process also means that the legumes will cause less gas production in the gut (aka less farting).

Tempeh is great for people transitioning to a more plant-based diet for the first time. Shifting the diet to more beans and legumes as protein sources can sometimes cause bloating and gas initially. However, these side effects are significantly less likely with tempeh since it is fermented. The Rhizopus fungi that ferment the legumes into tempeh also make nutrients and vitamins from the legumes more readily available. Things get even healthier when you can use sprouted legumes to make tempeh! I love using sprouted lentils.

Making Tempeh at Home

I have to say, that making tempeh has been quite fun. I decided to start making my own more often in 2020 in an effort to reduce plastic consumption in our home. I’ve been experimenting with various beans and grains, figuring out which flavors of legumes I enjoy the most. Pictured in this blog is my sprouted lentil tempeh. I enjoy the sprouted lentil tempeh the most, and it’s probably the only kind I will continuously make. At first, tempeh can seem like a laborious process, but it’s not so bad with a few tips and tricks.

Dehulling the Legumes

Dehulling is essential for proper tempeh fermentation and quality.

I like soaking my legumes for about 12 hours and allow them to sprout before I rinse them and boil them. A lot of the hulls naturally come off during this process! Sprouting is the most effective way to remove hulls. Once they’re sprouted, I put the legumes in a bowl of cold water. Then I just rub them between my hands in the water until a lot of the hulls float to the top. The hulls are easily poured off. You don’t have to remove every single hull, the tempeh will still come out fine. Also, I find that it’s easier to remove the hulls of bigger legumes, like chickpeas. More hulls come off when you cook the lentils too. When cooking, you want them to be tender but not mushy. The legumes should be firmer than if you were cooking them to eat right away. It’s important to not overcook.

Drying Out the Legumes

For this fermentation to come out delicious and safe to eat, you have to dry the legumes that you just cooked. Do NOT put them in a dehydrator or anything, you are not trying to dry them out that much. I like to spread the cooked legumes out on a clean sheet pan and let them air dry for about 2-4 hours. A trick I use to make sure they are dry enough is adding rice flour to my recipes. Tempeh ferments great with rice anyways, so it’s a great way to ensure things stay dry enough for the Rhizopus mold to thrive.

The cooked legumes have to be more on the dry side, and the material the tempeh is wrapped in has to be breathable (either with holes or made from a porous material). The breathable material provides oxygen to the aerobic fungi, and in tandem with dryness prevents anaerobic spoilage microorganisms, like Bacillus spp. and Clostridium spp. These are the worst contaminant that we need to worry about with tempeh. These contaminants usually result from too much heat and too much moisture. You’ll know if the tempeh hasn’t fermented properly when you smell it. It’s very hard to miss.

The Ingredients

The ingredients here are pretty simple. You just need four things.

1. 2 Cups of legumes of your choice: The only tempeh I make consistently is sprouted lentil tempeh. The flavor is mildly nutty and wonderful. I personally think the flavor of chickpea, lentil, and soybean tempehs are the best.
2. 2 Tablespoons Rice Vinegar: Always use pasteurized, filtered vinegar. Do not use raw apple cider vinegar. The microbes in raw vinegar will disrupt the Rhizopus.
3. 2 Tablespoons Rice Flour or Chickpea Flour: This is to help keep the fermentation environment dry enough to prevent spoilage.
4. 1 Teaspoon Rhizopus Tempeh Starter Culture: Click HERE for the tempeh starter that I’ve been using. After making your first batch of tempeh, you can dry out a piece of tempeh in a dehydrator and use it as a starter for your next batch.

Tempeh Starter Culture

Let’s talk a little bit about the fungus that makes tempeh! It’s called Rhizopus and it’s a pretty cool fungus. Rhizopus is a genus of filamentous fungi that are commonly found in nature, on food and in association with animals. Rhizopus fungi are characterized by a body of branching mycelia composed of three types of hyphae: stolons, rhizoids, and usually unbranching sporangiophores. This complex mycelium is what holds tempeh together in a uniform, dense mass. Multiple species of Rhizopus can be used to make tempeh, but the most common species used it R. oryzae.

Equipment and Supplies

You have to tightly wrap the cultured legume mixture in a bag or something similar. Honestly, I absolutely HATE using plastic to make tempeh. I think the most problems arise when plastic is used because the plastic holds too much condensation and moisture. This leads to nasty results and undesirable microbial growth.

Banana Leaves work best since they are porous and you can sometimes find these at the Asian market. Another option is bamboo leaves. You can also use a plastic bag with holes poked in it (my least favorite), or cheesecloth (but you’ll have to wrap with a few layers and discard it after). You’ll also need something heavy like a large cutting board or a textbook to press the legume mixture into a dense cake. If you need to use a plastic bag, I suggest using plastic bulk section bags from the store like the one pictured here. I have a few of these bags from grocery store trips in which I forgot to bring my reusable bulk section containers. I get really great results using these because they’re more porous than a ziplock.