Solution:

1. Boil for 2 minutes first. You can fry for a while longer. The bitterness will become smaller when the oil is added. When making tempeh, you need to control the softness and hardness of the beans. If they are cooked too soft, the tempeh will have a bitter taste.

2. Let it ferment. When fermenting, try to use a bamboo container, first lay a layer of straw on the bottom of the container, or not. When fermenting, you should also pay attention not to spread the beans too thickly, nor too thinly. Too thick is not conducive to ventilation, and too thin will cause the water to evaporate too quickly.

3. After fermentation is completed, each bean will be wrapped with a layer of white or green stuff. Take it out and wash it with water first, then with wine. After washing with wine, do not touch it with water again and seal it in the jar.