The so-called 'firewood, rice, oil, salt, sauce, vinegar, tea', as an essential seasoning for daily cooking, vinegar cannot be ignored. How to choose vinegar? What are the key indicators that vinegar can refer to? So, today I will talk to you all. Vinegar making is a lengthy chemical reaction process that follows the principle of using grains to make vinegar. First, the grains are steamed (cooked with water before microorganisms can digest them), then mixed bacterial strains (yeast) are inoculated to use various amylase enzymes secreted by microorganisms to convert the starch in the grains into sugar (saccharification). Then, yeast is used for anaerobic fermentation to produce alcohol (ethanol), which is then converted into acetic acid by acetobacter. This chemical reaction process has been studied by middle school students. So theoretically speaking, making vinegar is even harder than making wine, with a longer process and greater labor consumption. Coarse grains, wheat, rice, potatoes, corn, etc. are all raw materials for vinegar. The raw materials for vinegar are quite diverse, and each region has its own unique vinegar. For example, traditionally in the north, various small grains such as sorghum, millet, buckwheat, barley, etc. are produced and can be called the main raw materials for vinegar production. Some products also add some starch beans. The rich flavor of aged vinegar is the epitome of mixed grain vinegar; In the Central Plains region, there is more wheat, so wheat has become the main raw material for vinegar production; Jiangnan is rich in rice and mainly uses glutinous rice and rice to make vinegar. Soft and sweet glutinous rice vinegar belongs to this category. Rice is cultivated in the Beijing Tianjin area, and rice vinegar made from rice is also very popular. In addition, starchy raw materials such as potatoes, sweet potatoes, and corn can also be used to make vinegar. When making vinegar, bran is often added, and adding it in moderation is also beneficial. Because bran contains a large amount of B vitamins and minerals, it is beneficial for promoting the growth of vinegar brewing microorganisms and increasing the content of trace nutrients in vinegar. Fruit vinegar is made from fruits or dried fruits, such as apple vinegar, grape vinegar, persimmon vinegar, date vinegar, etc. Fruits and dried fruits are rich in sugar, which eliminates the troublesome step of starch saccharification. At the same time, fruit vinegar also adds other organic acids such as citric acid, malic acid, tartaric acid, etc. contained in the fruit itself. The sour taste is different from grain vinegar, and it also carries some fruity aroma, making it particularly delicious. Some vinegar is partially or entirely made from alcohol. With low alcohol Baijiu or edible alcohol as raw materials, saccharification and alcohol fermentation are omitted, so the speed of vinegar brewing is extremely fast, and it can be completed in two or three days. The vinegar produced in this way has not undergone the complex fermentation process in the early stage and does not have the "browning" caused by the Maillard reaction, so the color is very light and the acetic acid content can be very high. The white vinegar purchased on the market is often made directly with alcohol, or by adding a small amount of rice and alcohol together. The nutritional value of aged vinegar made from miscellaneous grains and beans is very high. During the vinegar brewing process, the B vitamins and minerals such as calcium, iron, and zinc in the grains can all be incorporated into the vinegar. This is because most B vitamins prefer acidic environments, such as vitamin B1 and vitamin B2, which are substances that are sensitive to acidity and alkalinity. Meanwhile, the insoluble compounds of calcium, iron, and zinc in grains will largely dissociate into ionic states in acetic acid and dissolve in the vinegar solution. Various polyphenolic antioxidants contained in miscellaneous grains can also run into vinegar and remain stable in vinegar for a long time. So, compared to beverages, vinegar has much higher nutritional value. Especially for aged vinegar made from miscellaneous grains and beans, its rich calcium, potassium, magnesium elements, and B vitamins are comparable to milk. However, milk can be consumed in a large glass, while vinegar can only be consumed in a spoon, so the actual daily intake of nutrients is not that much. Nevertheless, the nutritional value of high-quality vinegar is enough to surpass other seasonings. What are the added ingredients in vinegar? In addition to the vinegar ingredients mentioned above, vinegar often contains some non essential ingredients. 1. Sugar: In order to neutralize acidity and soften the taste, a small amount of sugar, syrup, or sweetener is often added to make the taste softer and richer. Especially the fragrant vinegar that southerners love to eat, its sweetness is relatively strong because it contains a lot of white sugar. Of course, vinegar is not a drink to be consumed in a large glass, and even with a little sugar added, there is no need to worry about consuming a large amount of sugar as a result. 2. Salt: Regulating microbial fermentation. Compared to soy sauce, salt is much less and needs to be added during the brewing process. In addition to seasoning, it also plays a role in regulating the microbial fermentation effect. But compared to soy sauce, vinegar contains much less salt. So there is no need to worry about excessive sodium intake due to adding two spoons of vinegar. On the contrary, adding vinegar can make dishes with less salt taste more vivid and help people happily reduce salt. 3. Freshness enhancer: Commonly used is monosodium glutamate (MSG). In order to make vinegar more delicious, some vinegar products also add freshness enhancers, such as monosodium glutamate (MSG). In fact, under the acidity of vinegar, monosodium glutamate cannot exert its maximum umami effect. However, when vinegar is used to make seasoning sauce or mixed with cold dishes, the acetic acid is diluted, and the acidity of the dish may be in the weak acidic range. At this time, monosodium glutamate can fully exert its freshness. 4. A small amount of preservatives: usually products with concentrations of potassium sorbate, sodium benzoate, and sodium dehydroacetate that cannot fully inhibit bacteria at room temperature require a small amount of preservatives approved for use in China, such as potassium sorbate, sodium benzoate, and sodium dehydroacetate, similar to soy sauce. In addition, some other seasonings that do not add enough oil and salt often add these preservatives. Products with an acetic acid content of 6% or with a large amount of salt added do not require the addition of preservatives. 5. Other flavor ingredients include vinegar, which is added to other flavor ingredients to make dumpling vinegar with garlic, ginger juice vinegar with ginger, seafood vinegar with ginger, cooking wine, and seafood seasonings. Buy vinegar according to the following points: 1. Pay attention to what type of vinegar it is. If you want a softer and sweeter taste, you can choose fragrant vinegar made from glutinous rice; If you want a stronger and richer flavor, you can choose aged vinegar; If you want a refreshing taste, you can choose rice vinegar. Each region has its own taste habits. People in Beijing and Tianjin like to dip rice vinegar in dumplings, Shanxi people like aged vinegar, and people in the Yangtze River Delta prefer fragrant vinegar. Shaanxi has bran vinegar, Fujian has red vinegar, and there are well-known products recognized by residents in various regions. When cooking, certain dishes require the use of specific vinegar. West Lake Fish in Vinegar Sauce is delicious only with aromatic vinegar, Hot and sour soup is delicious only with mature vinegar, and it is refreshing only with white vinegar brewed with shredded lettuce and purple cabbage. Some Western cuisine requires the use of grape vinegar or apple cider vinegar to feel the authentic exotic flavor. It is not possible to directly compare the quality between different types of vinegar. We can only compare the quality of different products of one type of vinegar. However, in terms of nutritional value, aged vinegar is an insurmountable height. Its minerals such as calcium and iron, B vitamins, and antioxidant components are all top-notch, because it concentrates trace nutrients from miscellaneous grains. Vinegar with a light taste usually has lower nutritional content. However, since the amount of vinegar used is limited, providing nutrients is not its primary function. 2. Pay attention to the indicator of "total acidity", which requires 3.5% to meet the standard. The higher the acidity, the better the quality. The reason why vinegar is sour is because it contains acetic acid and a small amount of other organic acids. These acids can dissociate hydrogen ions, making the tongue feel sour. According to Chinese regulations, vinegar products must have a total acidity of at least 3.50% in order to be sold as qualified vinegar. Generally speaking, except for white vinegar, vinegar with higher acidity in similar products will have better quality, as this means that the concentration of flavor components in the product is high or has been aged. Although vinegar is not as salty as soy sauce and has a salt content similar to that of everyday heavy mouthed dishes, it also has a "natural antibacterial component" that inhibits microbial growth, which is organic acids such as acetic acid. So, the higher the total acidity, the stronger the antibacterial ability. 3. Pay attention to whether it has been aged, how long it has been aged to produce vinegar mash, and after pouring out vinegar juice, it can also undergo a long aging process to allow the water in it to slowly evaporate. Some of the pungent acetic acid also evaporates, while various non-volatile organic acids, sugars, and amino acids in vinegar are continuously "concentrated", forming the product of aged vinegar. After aging, the acidity of vinegar will gradually increase. When the total acidity exceeds 6%, it can be stored at room temperature for a long time without the trouble of microbial proliferation, and there is no need to add preservatives. The longer the aging period, the more concentrated the umami and sweet substances, the less pungent the vinegar flavor, the richer the organic acid composition, and the longer the vinegar aftertaste. At the same time, the trace nutrients in vinegar have also been concentrated. Aging not only takes years and months, but is also a process that takes up space, labor, and continuously reduces volume and weight. So, for vinegar of the same type and brand, the longer the aging time, the higher the price of vinegar. Generally speaking, vinegar that has been aged for 3-6 years can already achieve good edible quality. Vinegar that has been aged for more than ten to several decades is quite expensive, just like aged wine, which is beyond the scope of ordinary consumers' daily cooking. 4. It requires a significant amount of cost to ensure that the product's certification mark meets the production standards for organic and green food, and has passed the relevant certifications. So these certified products, under the same aging time, will be priced higher than similar products. Obtaining these certified products provides greater assurance in terms of pesticide residues and toxic elemental pollutants. However, this does not mean that their taste is better. Qualified products sold in large supermarkets must meet the standards for their main pollutant residues. Moreover, vinegar is only a small edible product, and the total amount of environmental pollutants it can bring is limited. Some products have "geographical indication" certification, indicating that they are locally unique high-quality products. Don't worry too much about whether it is zero added or sugar free. As for whether it is "zero added", "sugar free", "gluten free", etc., don't worry too much. These are all concepts of stir frying, which do not necessarily mean that the product is of higher quality or more delicious. After all, vinegar is a seasoning, and the better its flavor, the greater the significance of buying it, provided that its safety is qualified. For the sake of certain concepts or to save money, buying low-quality vinegar or "sour seasoning liquid" that cannot even meet the standards for brewing vinegar is deceiving oneself and one's family. It should be noted that nowadays, any product called "vinegar" must be brewed vinegar. So consumers no longer need to bother distinguishing whether a brown vinegar is fermented or made with glacial acetic acid, caramel coloring, salt, and sugar. So, is there still the same kind of "mixed vinegar" used in the past? There are still products of this kind, but they can only be renamed as "vinegar flavored seasoning sauce". It is an acidic liquid compound seasoning produced using a formulation process. So, when buying vinegar, you need to confirm whether you are buying vinegar or some sour "seasoning sauce" or "compound seasoning". (New Society)