Step 1

Cover the soybeans with water and soak for 12 -18 hours. If you are using the dry method for dehulling, pass the beans through a grinder at this point. Otherwise, dehull after boiling. See the section above for more information.

Step 2

Bring the soaked soybeans to a boil and simmer until they are soft but not mushy about 1 hour.

Step 3

Drain the soybeans and gently pat them dry with a towel, then allow them to cool to just below body temperature.

Step 4

Mix in the vinegar (to lower the pH so that unwanted bacteria won’t grow).

Step 5

Sprinkle on the tempeh starter and mix well so that the beans are evenly covered by the spores.

Step 6

Fill the fermentation container(s).

Step 7

Incubate at approximately 88 F (31 C).

Step 8

Check the beans after 12 hours. At this point, the mold will have started to grow and the beans will start generating heat. You may need to lower the temperature.

Step 9

At some point between 24 and 48 hours, your tempeh will be finished. You will know it’s done when the mold has thickened the soybeans into a single dense mass. There might be some grey or black mold spores, but you want to stop before it spores. See the photo above for a picture of the white mold.

Step 10

At this point stop the fermentation by transferring the tempeh to an airtight container and storing it in the refrigerator for up to 1 week. (See notes for cooking and freezing instructions).