The pigments are mainly phenolic substances such as anthocyanins. Their color constitutes the color of the wine and brings their own aroma and delicate taste to the wine. The color in aged wine is mainly derived from tannins which can not only make contribution to the color and luster of the wine, but also act on one's mouth to produce a bitterness, thereby promoting one's appetite. If tannin content is too high, the wine will have great bitterness and rough quality; and if it is too low, the wine will be diluted. In addition, tannin can also mask the sourness
red wine is significantly less acidic than white wine due to its rich tannins.
Tannins can affect the color of wine and the taste and appetite of drinkers.