According to the definition of wine, wine is fermented from grapes, and its quality depends on raw materials first, and then on technology. The production process of wine is the process of concentrating the excellent potential of grape raw materials and perfectly embodying it in wine, so as a wine, it should have the aroma of grape varieties, the aroma produced by fermentation and the aroma produced by aging. This taste should be pleasant, complex and layered. The so-called aroma of grape varieties, which is usually called fruit aroma, should come from nature-grapes, not artificially added.

In wine, wine can be divided into several types according to different varieties of raw materials and different technological requirements. In terms of color, wine can be divided into red wine, white wine and pink wine, which mainly depends on the amount of pigment on the grape skin during fermentation. In addition, according to the different sugar content of the final product, wine can also be divided into dry wine, semi-dry wine, semi-sweet wine and sweet wine.

The quality of wine can be judged from three main aspects, namely, physical and chemical indicators, hygiene indicators and sensory indicators. Among them, physical and chemical indicators are the most basic characteristics of wine, that is, the minimum content of components that should be achieved, such as alcohol content, sugar content, acidity, sulfur dioxide and so on. Hygienic index is to measure the degree of wine pollution by microorganisms or heavy metals; Sensory index is an important method to judge the quality of wine and a comprehensive evaluation of wine quality.

Faced with a wide variety of alcoholic products, consumers need to carefully and scientifically purchase and consume.

First of all, judge the quality from the implementation standard. According to the provisions of China's food labeling standards, the label of wine should be marked with the standards for product implementation. At present, there are three standards implemented in the wine industry: the first is the national standard GB/T 15037-94 "Wine", which requires that the product is made of grapes or grape juice by complete or partial fermentation, and the alcohol content is greater than or equal to 7% (v/v), and other requirements are stipulated. The wine produced according to this standard is the real wine. The second is the industry standard QB/T 1980-94 "Half Juice Wine". It defines the products as non-native wines blended with 50% or more wine, which are mixed with different amounts of water, alcohol and additives. The third is the enterprise standard starting with Q. At present, the quality of products implementing such standards varies greatly. Some enterprises set standards higher than the national standards, and some enterprises, especially some small enterprises, set standards far below the requirements of national standards and industry standards, which are simply tailor-made for inferior wines.

Therefore, the quality level of wine can be roughly judged only from the standards implemented by enterprises. Generally speaking, the products that implement the national standard should be wines with good quality; The quality level of standard products is generally lower than that of national standard products; Products that implement enterprise standards are generally poor or even inferior in quality, except for a few large enterprises that have formulated enterprise standards higher than those recommended by the industry or the state. Especially in the standard provisions, some enterprises set the index of "dry extract" far below the national standard or line standard, and some even avoided this index and did not stipulate it at all. This wine must be artificially blended, not fake wine. In addition, the products of some non-standard production enterprises can not be included in the procurement.

Secondly, judge the quality from the level of alcohol. Alcohol content is a must on wine labels. According to the wine standard, the alcohol content of wine should not be less than 7% (v/v), the alcohol content of wine processed by normal technology should be around 1 1% (v/v), and some special products can be between 7% and 24% (v/v). When the alcohol content in wine is less than 7% (v/v), one reason may be the poor quality of grape raw materials; Another reason is that grapes are not fermented at all, both of which are the reasons for the poor quality of wine. In addition, the alcohol content is too low, which affects the shelf life of wine and the quality is difficult to guarantee.

Third, judge the quality from the sensory characteristics. Appearance: the appearance of good wine should be clear and transparent (dark wine can be opaque), shiny, its color is consistent with the name of the wine, and its color is natural and pleasing to the eye; Inferior wine, or dull, or the color does not match the name of the wine, no natural feeling, or bright color, but it has obvious artificial color feeling. Aroma: Wine is a fermented product, and its aroma should be fruity, fermented and aged, which should be balanced, coordinated and integrated, elegant and pleasant; Inferior wine does not have these characteristics, or it has a prominent and violent fruit flavor (with essence), or it has a prominent alcohol flavor, or it has other peculiar smells, which makes people hate it. Taste: the taste of any good wine should be comfortable and pleasant, with delicate and soft aroma, mellow and complete, distinct layers and long aftertaste; Inferior wine, or with peculiar smell, or outstanding aroma, or thin body without layering, or no aftertaste.