It uses wooden hams, small vats, wooden shovels, and wooden barrels to steam to reproduce the whole process of natural steaming ingredients.

The steamed raw materials are lowered to the appropriate temperature and put into a large vat. They are first fermented for three days and stirred twice a day with a wooden pallet. On the fourth day, it must be sealed with slates and cloth bags and fermented anaerobically for eighteen days. This fermentation process lasts for a total of twenty-one days. The old wine with a rich and fragrant aroma is brewed.

After the alcoholic fermentation is completed, a process of acidification is required. This process is exactly the opposite of the previous anaerobic fermentation of alcohol. It is an aerobic fermentation process that requires a large amount of oxygen as a catalyst to help it complete acetic acid fermentation. The purpose of manually turning the fermented grains every day is to allow the vinegar fermented grains to fully absorb oxygen. If you watch it live, you can hear the clanging sound, which is the sound made by the collision between the copper hand caps worn by the vinegar brewing masters and the cylinder wall. The function of this copper hand cap is to prevent acetic acid from corroding the skin of the fingers. Secondly, it can turn the fermented grains more thoroughly, so that the fermented grains can be in close contact with oxygen, so as to achieve complete fermentation of the fermented grains. After fifteen days of fermentation, the vinegar fermented grains with strong sour aroma will be mature.

Put the mature vinegar fermented grains into a smoking vat and smoke it using a fire kang, a porcelain pot cover and a wooden shovel. Through this unique process, a complete and sufficient vinegarization process is completed. The fermentation and brewing process of mature vinegar has been further improved. One is to make the sourness of the vinegar when it is first fermented become sour and mellow. Second, it produces the unique aroma of aged vinegar; third, the color of the vinegar becomes a calm, quiet purple. In this way, the mature vinegar can have a good color, fragrance and flavor. Although the production cycle is extended, it also enriches the esterification process, perfectly reflecting the unique sour and sweet taste of aged acetic acid.

The ancient method of the Ming and Qing Dynasties is adopted, with high and low leaching, and cyclic leaching twice, so that it can be squeezed and leached cleanly without sedimentation. The top wooden barrel is filled with unsmoked white fermented grains, which is soaked in boiling water to flush out the acetic acid, and then left in the large pot below for high-temperature sterilization. Remove the cork in the middle and let it mix with the smoked fermented grains below. The wooden barrels are combined into one, and are finally left in the large vat below, where the original vinegar is poured out. It is also edible, but it needs to be aged to become a veritable mature vinegar.

The so-called aging is based on leaching out the original vinegar, and then going through an aging process of "sun-drying in the summer and ice-fishing in the winter". The so-called summer sun-drying means that the vinegar needs to be aged in a vat and allowed to be exposed to the sun in the summer. The purpose is to remove easily evaporated water and volatile acids; winter-glazing means that the specific gravity of vinegar is greater than that of water, and the ice will freeze in winter. Drain out the water to make the vinegar purer and the sourness more stable. According to statistics, when a jar of new vinegar is aged and more than half of the water is removed, the color can be black and purple, it will not become moldy in the summer, and it will not freeze in the winter, so that the vinegar can reach a high concentration.

The mature vinegar we usually eat is stored for more than half a year, while the old vinegar needs to be stored for at least one year. Therefore, the secret of old vinegar lies in the word "old". The longer it is stored, the better, and the longer it is, the more fragrant it is.