manufacturing method
There are four kinds of raw materials and production methods of vinegar. (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.
Liquid vinegar brewing technology There are many traditional liquid vinegar brewing technologies. 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.