Production method
Carefully select soybeans, remove bad and deteriorated beans and other impurities, wash them with clear water, put them in a pot and cook them with water. When the soup is clean, they must not be burnt, and the beans are extremely crisp and rotten by twisting them with your hands. Turn off the fire and stew them until the next morning, and the beans will be red. And then ground into uniform bean paste by a meat churn. Wet and dry sauce is suitable, and if it is too dry, it will be difficult to reunite into fermented grains, which will affect normal fermentation. If there is too much water, the fermented soy sauce will be too soft to form, and the fermented soy sauce core will be easily damaged by heat, insects and rancidity. Generally, the size of fermented soy sauce is 3 kg of dried beans, which is about 30 cm long and has a cross-sectional area of 20 cm 2, which is easy to ferment. Dry the fermented soy sauce in a cool and ventilated place indoors (about three or five days), then wrap a layer of kraft paper outside the fermented soy sauce (to prevent the corrosion of flies and insects, dust pollution, etc.), and put it in a cool and ventilated place. The fermented soy sauce can be stacked in layers for a long time, but separated by thin strips, and it will take about one week. To a certain extent, it is good to have white hair inside. Just do it.
Aspergillus oryzae As395 1 or Huniang 3042, which is the national preservation strain.
The answer adopted by the questioner is homemade soy sauce.
There are two ways to make soy sauce with Aspergillus flavus.
Full koji-making method: soybean and rice (or fried wheat) are made into koji in the same proportion of 7:3 6:4 5:5 and fermented with salt water.
Semi-koji-making method: make koji with rice or wheat, steam soybeans, add koji and salt water for fermentation.