Is all Pu-erh tea with a 'bitter and astringent' taste considered bad?

There are two main reasons why tea leaves have a 'bitter and astringent' taste: firstly, due to the presence of bitter and astringent compounds in the tea leaves themselves, and secondly, due to pest and disease damage. Therefore, one cannot simply categorize all Pu-erh tea with a 'bitter' taste as bad. Sometimes, tea with a 'bitter and astringent' taste can actually be good tea, because...

The intensity of the bitter and astringent taste in tea is determined by the amount of bitter and astringent substances it contains. The main bitter substances in tea include: caffeine, theobromine, theophylline, anthocyanins, tea saponins, bitter amino acids, and some flavanols. The bitterness in tea soup often accompanies astringency and plays a dominant role in the taste structure. Alkaloids in the tea soup form hydrogen bond complexes with a large amount of catechin substances. In teas with relatively high contents of both catechins and caffeine, the tea soup is strong, mellow, and refreshing, which is a characteristic of high-quality tea. In terms of a tea plant branch, the bitter substances that determine tea quality are often higher in tender leaves than in old leaves, especially the first and second leaves below the bud, which have the highest content of tea polyphenols and caffeine, decreasing sequentially. The main astringent substances in tea include tea polyphenols, aldehydes, iron, etc., among which catechins are particularly important. Esterified catechins have a strong bitter and astringent taste, and their content in buds and leaves is much higher than in coarse old leaves. Normally, tea products made from tender one-bud-one-leaf or one-bud-two-leaf sets have a much stronger bitter and astringent taste than those made from one-bud-three-leaf or one-bud-four-leaf sets. Therefore, Pu-erh tea with a 'bitter and astringent' taste is often made from high tenderness and high-grade leaves. This is also why medium and low-grade teas have a relatively bland taste. For Pu-erh tea, any tea product with high tenderness, evident aged aroma, and low bitterness is undoubtedly an aged tea, resulting from the extensive degradation and transformation of bitter and astringent substances over long-term storage, making the taste mellow.

Another abnormal situation is that tea made from leaves severely damaged by pests and diseases often has a heavier bitter and astringent taste than normal leaves, even exhibiting 'foul bitterness' or a 'fishy odor.' In Yunnan tea areas, common diseases affecting tender tea leaves include tea blister blight and tea white scab. Products made from leaves infected with tea blister blight taste bitter and are brittle; those made from leaves infected with tea white scab taste bitter, fishy, and can cause discomfort in the stomach after consumption. Many sap-sucking pests can also increase the bitter and astringent taste of tea products after infesting tea plants. In Yunnan, these mainly include tea green leafhoppers, tea thrips, tea aphids, black citrus aphids, tea false spider mites, and tea lace bugs. Teas affected by pests and diseases can be identified by examining the brewed leaves (tea residue). If there are many diseased spots or insect-damaged leaves and the taste is 'foul bitter,' it is considered bad tea and not worth storing.

Tea products made from tea gardens that have been subjected to long-term single application of chemical fertilizers or from tea plants with purple buds and leaves also tend to have a stronger bitter and astringent taste. Tea from long-term single application of chemical fertilizers shows no abnormalities in the brewed leaves, but the bitterness is stronger than the astringency; tea products processed from purple buds and leaves have indigo-blue brewed leaves and both bitterness and astringency are strong.

Related links: Golden Pearl Pu-erh, Golden Flower Fu Brick Tea