The composition of red wine is quite complicated. It is a fruit wine brewed by natural fermentation. It contains the most grape juice, accounting for more than 80%, followed by alcohol, which is naturally fermented by the sugar in the grapes, generally 10-13. %, there are more than 1000 kinds of remaining substances, more than 300 kinds of more important ones. Other important components of red wine, such as alcoholic acid, fruitiness, minerals and tannins. Although the proportion of these substances is not high, they are the decisive factor for the quality of wine. The red wines with high quality and delicious taste are because they can present a kind of balance of organization structure, which makes people have endless enjoyment in taste. Wine is not only a solution of water and alcohol, it has rich connotations: A. 80% water. This is pure water in the biological sense, which is drawn directly from the soil by the vine. B. 9.5-15% ethanol, the main alcohol. It is obtained after fermentation of sugar, which is slightly sweet and gives the wine a mellow taste. C. Acid. Some are derived from grapes, such as tartaric acid, malic acid and citric acid; some are produced by alcohol fermentation and lactic acid fermentation, such as lactic acid and acetic acid. These main acids play an important role in the acidic flavor and balanced taste of wine. D. Phenolic compounds. 1~5g per liter, they are mainly natural red pigments and tannins, which determine the color and structure of red wine. E. 0.2~5g sugar per liter. Different types of wine contain different amounts of sugar. F. Aromatic substances (hundreds of milligrams per liter), they are volatile and there are many types. G. Amino acids, proteins and vitamins (C, B1, B2, B12, PP), they affect the nutritional value of wine. Therefore, drinking wine in moderation is beneficial to human health. It can protect blood vessels, prevent arteriosclerosis, and lower cholesterol.