manufacturing method
(1) The raw materials of traditional fermented vinegar in China are mainly glutinous rice and rice (japonica rice) in the south of the Yangtze River and sorghum and millet in the north of the Yangtze River. Nowadays, broken rice, corn, sweet potato, dried sweet potato, potato and dried potato are used as substitutes. Raw materials are cooked, gelatinized, liquefied and saccharified to convert starch into sugar, then ethanol is produced by yeast fermentation, and then ethanol is oxidized by acetic acid bacteria to produce acetic acid.
(2) fermented vinegar, a sugar-containing raw material, can be used to brew all kinds of juice vinegar from grapes, apples, pears, peaches, persimmons, dates and tomatoes, and honey and molasses can also be used as raw materials. They all only need to go through two biochemical stages: ethanol fermentation and acetic acid fermentation.
(3) Using ethanol as raw material, adding acetic acid bacteria for fermentation is only one biochemical stage. For example, it takes only 1 ~ 3 days to brew wine vinegar with low-alcohol liquor or edible alcohol diluted with water as raw materials by rapid brewing method.
(4) White vinegar is vinegar with a flavor similar to that of fermented vinegar by adding water to edible glacial acetic acid and adding seasonings, spices, pigments and other substances.
manufacturing technique
Solid state method
Solid vinegar brewing technology, there are three traditional solid vinegar brewing technologies.
1. Daqu vinegar production: sorghum is used as the main raw material, and after low-temperature saccharification and alcohol fermentation by enzymes secreted in Daqu, half of the aged vinegar residue is put into a fumigation tank, heated with slow fire, then soaked in the vinegar solution leached by the other half of the aged vinegar residue, and then new vinegar is leached. Finally, after three days of drying and ice fishing aging, the new vinegar is made into vinegar with deep color, thick texture, mellow sour taste and special flavor. The famous is Shanxi mature vinegar.
2. Xiaoqu vinegar making: glutinous rice and rice are used as raw materials, and microorganisms such as Rhizopus and yeast in Xiaoqu (also known as wine medicine) are used to cultivate bacteria on rice grains in solid state for saccharification and fermentation. Add water and wheat starter, and continue saccharification and alcohol fermentation. Then wheat bran was mixed into the mash to form a solid state, and then high-quality vinegar grains were added as seeds, and the propagation of acetic acid bacteria was gradually expanded by solid-state layered fermentation. After aging with vinegar, the vinegar juice is leached by leaching method, mixed with fried rice yellow and white sugar, clarified, and heated to boil to obtain balsamic vinegar. The famous one is Zhenjiang balsamic vinegar.
3. Using bran as the main raw material, using glutinous rice or Polygonum hydropiper juice to make vinegar mother for acetic fermentation, and aging the vinegar residue for one year to make bran vinegar with unique flavor. The famous ones are Sichuan Baoning (now Langzhong County) bran vinegar and Sichuan Quxian Sanhui specialty vinegar.
Solid vinegar brewing method uses wild microorganisms in nature, so the fermentation period is long, and the fermentation of acetic acid needs to be turned over, which is labor intensive. The fermented grains are fermented with alcohol, and then the vinegar fermented grains made of pure cultured acetic acid bacteria are fermented with acetic acid to obtain vinegar. There is also an enzyme liquefaction ventilation reflux method. The raw materials were soaked in water, ground into pulp, added with bacterial α-amylase, heated and liquefied, then added with bran koji for saccharification, cooled the saccharified mash, and added with distiller's yeast for alcohol fermentation. After alcohol fermentation, the fermented mash, bran, chaff and vinegar mother are fully mixed and sent to an acetic acid fermentation tank with a false bottom. There are ventilation holes under the false bottom, which allow air to enter naturally and use naturally. The yield, vinegar yield and labor productivity of enzymatic liquefaction ventilation reflux method are higher than those of traditional method.
Liquid method
There are many traditional brewing techniques of liquid vinegar.
1. Take rice as raw material, steam it, naturally mold it in the tank, then add water to make it into liquid, and ferment it at room temperature for 3-4 months. After the mature vinegar mash is pressed, clarified, disinfected and sterilized, the finished product with bright color, fragrant smell, no pungent and sour taste and mellow taste is obtained. The famous is ginger rose rice vinegar.
2. Using glutinous rice, red rice and sesame as raw materials, natural liquid fermentation was carried out by adding in stages, and after three years of aging, white sugar was added at last to get the finished product. The famous is Fujian monascus vinegar.
3. Thin wine is used as raw material, and acetic acid is used to ferment in a packed rapid brewing tower, such as white vinegar in Dandong, Liaoning.
The new technology of submerged fermentation is gradually adopted in vinegar production by liquid fermentation. After liquefaction, saccharification and alcohol fermentation of starchy raw materials, the wine mash is sent to the fermentation tank, and then the acetic acid bacteria liquid which is gradually expanded by pure culture is inoculated. The product temperature and ventilation rate are controlled to accelerate the oxidation of ethanol to generate acetic acid and shorten the production cycle. There are many kinds of fermenters, and now self-priming aeration fermenters have been used. It was first used in vinegar production by the Federal Republic of Germany in the early 1950s, and it was called Frings acetic acid fermentor, with patent 1969. Japan and European countries have adopted it. China has been using it since 1973.