Green and Black Tempeh Making

How to make tempeh at home in two beautiful colors – green and black!

日本語は、こちらから。

Since I shared two ways to make tempeh – one using whole beans and one using okara (soy pulp) – I’ve been making tempeh at home and this time I wanted to see if I could add a little twist to the regular whole-bean tempeh by using colored beans.

I thought about using different types of beans (like kidney beans or black beans) but read that tempeh mold doesn’t grow very well on beans other than soybeans. Luckily, Japan, being a country of diet rich with soybeans, produces more than one kind of soybeans! So for this tempeh making, I decided to use green soybeans (aobatamame) from Yamagata prefecture and black soybeans (kuromame) from Hokkaido.

So, as some of you might know, soybeans are green before they fully mature, and soybeans that are harvested early become “edamame” (green beans in pods). Aobatamame is an interesting type of soybeans because it doesn’t lose its green color even after it fully matures. The taste is also similar to edamame.

Kuromame is almost always cooked with sugar (and soy sauce) and is a common dish to serve for New Year. The taste is a lot sweeter than that of regular soybeans. While the skin is black, the actual bean itself is yellow just like regular soybeans.

To prepare the beans, soak 250g beans in 1,000ml water and 50ml vinegar overnight. Next day, peel the skin off of beans. It does take time but it’s better to be quite meticulous with peeling because the skin, if left unpeeled, would prevent the tempeh mold from growing on the beans.

After peeling, cook the beans with same solution (1,000ml water and 50ml vinegar) for 30 min until they get soft. For the black beans, to ensure that the color gets transferred to the beans, I used the same solution that was used for soaking (without the skin).

After cooking, drain the beans and let them cool and dry. Make sure you keep the beans covered while they cool down to prevent them from catching unwanted germs from the air.

Prepare the tempeh mold by combining 1/2 tsp tempeh starter with 1 Tbsp starch. The starch works as a filler so the tempeh mold gets distributed evenly to each bean.

Once the beans are cooled to the temperature of about 40 degree Celsius, combine the beans with the tempeh mold mixture. Mix well to coat each bean with the mold mixture.

Fill a shallow glass container with the beans and cover with plastic wrap. Take a tooth pick and make holes (about 2cm apart from each other). This is to ensure that the mold gets oxygen to breathe.

Place the containers in a cooler box or a styrofoam box. To keep the box warm, I put my yogurt maker set at 45 degrees in the box then placed the lid on (but not closed tightly – remember, the mold needs oxygen to breathe!). If you live in a tropical environment or have a room that is very warm all year around, there is no need to use this warming system. If you don’t have a yogurt maker, any type of warmer should work also.

After 20 hours of fermentation, my tempeh came out perfectly! When beans are covered nicely with white mold, that means that your tempeh is ready. If you over-ferment, the white color changes to gray and black, which has happened to me before. There is no need to throw away the tempeh! You just need to remove the over-fermented parts before cooking. (They are actually safe to eat, but the taste is quite bitter so it’s better to remove them.)

Tempeh in the middle is the regular one which I bought from a store, and you can see that the green and black colors came out beautifully and also mold layer is nice and thick on my homemade tempeh! I think next time I will try using the liquid for soaking to cook green soybeans also. That should intensify the green color on the resulting tempeh:)

It does take some effort to make whole bean tempeh at home, but I think it’s well worth the effort and once you get used to it, it’s really not that hard to make. I just make a big quantity and freeze them in small quantities as fresh/raw tempeh is good for only 2-3 days in the fridge.

Next time, I will share a simple pasta recipe using homemade tempeh!

Green and Black Tempeh

Ingredients

• 250g green soybeans (dry)
• 250g black soybeans (dry)
• For soaking and cooking (for 250g of dry beans)
• • 1,000ml water
• • 50ml vinegar
• 1/2 tsp tempeh starter
• 1 Tbsp starch

Instructions

1. Soak beans in water & vinegar overnight. Next day, peel the skin off of the beans.
2. Cook the beans in water & vinegar for 30 min until beans get soft. To ensure best color results, use the same liquid that was used to soak the beans.
3. Drain, cover and let the beans cool and dry.
4. Combine tempeh starter and starch.
5. Once the beans cool down to the temperature of about 40 degrees Celsius, add the tempeh mold mixture and mix wel.
6. Fill shallow glass containers with the beans and cover with plastic wrap. Take a tooth pick and make holes (about 2cm apart from each other).
7. Ferment in warm temperature (30-40 degrees Celsius) for about 24 hours until the beans are covered with white mold.