1, cooked and mixed with koji: firstly, the millet is pre-soaked, and the debt soaking time is 12 ~ 16 hours in spring and winter; 8 ~ 10 hour is suitable for summer and autumn. Then, take out the millet and steam it for 10 minute, and then sprinkle a proper amount of cold water on the rice layer; After steaming 10 minutes, the millet will swell and glow, soft and not stick to teeth, indicating that it is ripe. Wash the rice with cold water to reduce the temperature. After the water is controlled to dry, spread it on a bamboo mat and add yeast medicine.

2, into the altar wine: then into the altar, the jar of wine should be a pottery altar with a small mouth and a big belly. Pour the raw materials mixed with koji into the jar, and cover the jar mouth with a big quilt. 12 hours later, the microbial strains in the koji slowly propagated, and after 24 hours, the faint alcohol smell could be smelled, and after 36 hours, the wine slowly oozed out.

3. Water vinegar: In the whole process of alcohol fermentation, saccharification and liquor fermentation should be carried out separately, mainly saccharification in the early stage and alcohol fermentation in the middle and late stage. In order to make saccharification complete, it is necessary to brew wine again for 3 ~ 4 days to promote the conversion to a large amount of ethanol. When the wine starts to sour, cold water should be added four times every 50㎏ white rice to reduce the alcohol content and facilitate the growth and development of acetic acid bacteria.

4. Coloring of finished products: Generally, it takes 40-50 days in spring and summer and 20-30 days in summer and autumn, and vinegar turns sour and becomes perfect. Millet vinegar is light yellow in color, sweet and sour, and fragrant.