Tannin in wine is a common polyphenolic compound that is commonly found in plant skins, leaves and immature fruits. When tasting wine, you can feel the effect of tannin in wine. Dryness and subtle bitterness.

Wine is a kind of fruit wine made from grapes. Red wine is made from grapes with red skin and white flesh or red skin and flesh, which are fermented by a mixture of grape skins and juice. Still wine: Wine that does not contain its own fermentation or artificially added CO2 is called still wine, that is, still wine.