1, tea is bitter, mainly because of caffeine. The astringency is mainly related to polyphenols, and the sweetness is mainly derived from amino acids. These substances are dissolved in tea soup at the same time, and when combined with each other, the taste is fresh, strong and mellow, and there is no bitter feeling.

2. The bitterness and astringency of tea are caused by different reasons. In tea, the main bitter substances are caffeine, theobromine, anthocyanins and bitter amino acids. For example, if you think a certain kind of tea is bitter, it means that alkaloids contained in tea are dominant in tea soup. The sun-baked green tea in Laomanen Village, Brown Mountain, Menghai tea area, Yunnan Province, tastes particularly bitter. It has been proved by experts that the content of bitter theophylline in Laomang is particularly high, and bitter theophylline is one of alkaloids. Of course, this is only a special case, and most tea leaves do not contain bitter theophylline.

3. The main astringent substances are polyphenols (including catechins, phenolic acids, depsipeptive acids and other substances, among which catechins are the main components that affect the bitterness of tea soup). Generally speaking, the astringency in tea soup is often accompanied by bitterness, not "hemp", but slightly "hemp". Many tea friends who have just had tea friends will only feel that a certain tea is particularly bitter, but they can't clearly tell whether it has astringency. For example, when eating grapes, everyone likes to eat the pulp inside, and the grape skin will spit out because the grape skin is astringent; Or if we eat green persimmons, our tongue will feel numb, which is contrary to smoothness and has a convergent effect. This is the expression of astringency.