The pigments are mainly phenolic substances such as anthocyanins, and their color constitutes the color of the wine, and brings their own aroma and delicate taste to the wine. The color in the aged wine mainly comes from tannin. In addition to the wine In addition to contributing to the color and luster, it also acts on the mouth to produce bitterness, which promotes people's appetite. The tannin content is too high, the bitterness is heavy and the wine is rough. Ning also masks the acidity, so red wines are significantly less acidic than white wines because of their rich tannins. From this we can infer:. ['Aged wine promotes appetite, color comes from tannins.', 'Bitter and heavy wines must contain too much tannin.', 'Weak and thin wines must have too low tannin content.', 'Tannin can affect the color of wine and taste and appetite of drinkers.']