Many tea enthusiasts have had this experience: sitting in a tea shop drinking tea that is distinctly bitter and astringent, yet the tea artist says the new tea is more worth collecting the more bitter and astringent it is, indicating rich internal substances and excellent potential for later transformation. So the question arises: Is Pu-erh tea more worth collecting the more bitter it is?

To explore this issue, we must first understand what the flavor substances in tea leaves are. Tea flavor substances are the general term for all taste constituents in tea leaves that can be perceived by the sense of taste, composed of sour, sweet, bitter, astringent, umami, salty, and other taste elements.

So, what are the bitter and astringent substances in tea? According to Chen Zongmao's edited "China Tea Dictionary," the main astringent substances in tea are tea polyphenols, aldehydes, iron, etc., while the main bitter substances are caffeine, theobromine, theophylline, anthocyanins, tea saponins, bitter amino acids, and some flavanols.

The bitterness and astringency of tea soup accompany each other and play a dominant role in the taste structure of the tea soup. In the tea soup, alkaloids and a large number of catechin substances form hydrogen-bonded complexes. Therefore, the alkaloids and catechins in the tea soup have a synergistic effect on taste receptors and also constrain each other, forming the style of the tea soup.

Using professional testing instruments to analyze tea soup, the content of individual internal substances can be detected. However, when people drink tea, they can only perceive the comprehensive presentation of the tea soup. This comprehensive presentation refers to the performance where the internal substances in the tea soup cooperate and constrain each other.

If only bitterness is perceived during tasting, it indicates that bitter substances dominate in the tea soup, which can simply be understood as caffeine suppressing the presentation of substances like catechins.

So the question is, if the taste is very bitter, does it mean the tea leaves are rich in internal substances? The answer is not necessarily. Even if they are indeed rich, it also indicates that the internal components of this tea are not balanced, with an excessive content of bitter and astringent substances.

On the contrary, if a tea has abundant internal substances and a balanced combination among them, it often does not exhibit strong bitterness or astringency. Therefore, a balanced, full-bodied, and comfortable tea soup is the standard by which we measure whether a tea is worth collecting.