Step 1: Wash and soak
Measure a bowl of soybeans, about 110g, and wash it with water. (For 1L yogurt machine is 110g soybeans, if it is 1.5L\yogurt machine, 1.5 bowls of soybeans) Soak soybeans with 3 times the water, about 24 hours in winter, about 12 hours in summer, about 250g of soaked soybeans.
Step 2: Steaming
Put the soaked soybeans into the pressure cooker, pour in the right amount of water, cook over high heat for 5 minutes, turn on the heat and cook for 35 -40 minutes, turn off the fire. The beans are cooked to the point that they deflate when gently pinched by hand, but the beans are still whole. While still hot, scoop out the beans with a slotted spoon and pour them into the yogurt maker liner.
Step 3: Inoculation
Open a capsule of natto and dissolve it in a little bit of warm water, pour it into the inner liner of the yogurt maker, stir it well, as much as you can, cover it with a wet gauze, and wait until the temperature of the outer wall of the liner is not too hot, about 40 degrees, put it into the yogurt maker, and put on the outer lid (the liner's lid is not to be covered). If the temperature is low in the northern winter, you can put an appropriate amount of warm water between the inner and outer liner of the yogurt maker to increase the temperature.
Step 4: Fermentation
Plug in the yogurt machine power supply, start fermentation, fermentation time 16-24h, decided by the individual, the end of the fermentation is based on the natto with chopsticks to stir a little, can pull out a lot of silk.
Step 5: Storage and Cooking
After making the natto, if you can't finish it at one time, you can put it in the refrigerator for freezing and preserving, usually not more than 10 days. When you eat it again, when you take the natto from the refrigerator to room temperature, the natto will undergo a second fermentation, which will increase the degree of fermentation of the natto, and this process is also called after-ripening.