When speaking of tea’s flavors, tea lovers often quote the saying, “No bitterness, no astringency — it is not tea.” The so-called astringent sensation, also called the contracting sensation, is not actually a taste but a tactile feeling. It produces a “gripping,” tightening sensation in the mouth and on the tongue. In the ancient Chinese dictionary Shuowen Jiezi, the character for “astringent” is defined as “not smooth.”
The ancient and modern meanings are the same: the astringency in tea’s mouthfeel simply refers to a lack of smoothness. The astringent substances in tea leaves are primarily polyphenols, anthocyanins, and others, among which catechins are the most important.
On the one hand, astringency gives the tea liquor a sense of weight; on the other, it gives the liquor a powerful, vigorous quality. So how exactly does the astringent sensation in tea leaves arise?
It turns out that the polyphenolic substances in tea leaves contain free hydroxyl groups, which bond with the proteins in the epithelial tissue of the oral mucosa, coagulating to form an impermeable layer. The local muscles in the mouth contract, stimulating nerve endings and producing the astringent sensation. Simply put, it is the encounter and collision of tea polyphenols with the oral cavity that creates the feeling of astringency.
If there are many hydroxyl groups from the polyphenols — meaning a strong ability to dehydrate mucoproteins — the resulting impermeable film is thicker, and the astringency is more intense and lingering, like eating a raw persimmon. Conversely, if the film formed is thin and fragile, gradually breaking apart, it produces the taste of astringency followed by sweetness.
From this we can see that tea’s astringency is determined by its constituent substances and is an unavoidable, objective reality. If a tea had absolutely no astringency at all, it would indicate poor quality and low nutritional value.
As for the tea itself, the variety and grade of raw materials, growing environment, and harvest season all affect polyphenol content. However, the degree of astringency in a given tea can be controlled through skillful technique. Generally speaking, production methods, storage conditions, and brewing habits all influence a tea’s astringency.
Therefore, for thousands of years, Chinese tea makers have been exploring ways to improve tea processing and storage techniques, striving to reduce bitterness and astringency while enhancing drinkability.
Those skilled in brewing tea can also control astringency through steeping time, water temperature, and tea-to-water ratio. When handled this way, the astringency is mild, accompanied by bitterness, and then transforms into returning sweetness.
It is worth noting that if a tea with “astringency” has a clear, bright liquor, a clean mouthfeel, and the bitterness and astringency can dissolve away, producing saliva and returning sweetness — giving a sensation of sweetness after hardship — then this astringency comes from the tea itself. But if the bitter and astringent tastes are unnatural, with a clearly throat-locking sensation that requires your own saliva to dissolve, then this astringency is caused by human factors such as flawed craftsmanship, improper storage, or incorrect brewing — it is a defect.
Furthermore, as the astringent sensation continuously fades, cooling sensations and returning sweetness continually emerge. The saliva generated by the returning sweetness quickly restores smoothness to the mouth, and due to the contrast effect, this smoothness after dryness feels even smoother than usual.
—
Author: Old Tea Head · Lin Shen (LamSam)
Zen Tea Manor ZENTEA MANOR
Tianying Supply Chain Company
www.zentea-shop.com
