Bitterness and Astringency: Two Different Things

Many people drinking young raw pu'er for the first time frown and say, "So bitter and astringent." The two words often go together, but in tasting they're two different things: bitterness is a taste, astringency is a sensation. Once you can tell them apart, you'll know exactly what about a tea is bothering you, and how to adjust your brewing.

How Do Bitterness and Astringency Differ?

A simple test: if a bitter taste lingers at the back of your tongue after drinking, that's bitterness; if your mouth feels dry, your tongue feels like it's been rubbed with sandpaper, and your cheeks pull inward, that's astringency.

What Does It Mean When Bitterness "Dissolves"?

The tea world often says "the bitterness dissolves" or "the bitterness dissolves quickly," meaning that after the bitter taste appears, it fades within seconds and turns into huigan. This is an important feature of a good tea.

The opposite is "bitterness that doesn't dissolve": the bitter taste stays on the tongue, remains after you swallow, lingers for a long time, and no huigan follows. Possible causes include the raw material (some varieties or trees are naturally very bitter, with bitterness that lingers), processing (such as insufficient pan-firing), or brewing (steeping too long, water too hot, too much tea).

So when evaluating tea, the question isn't "is it bitter?" but "what happens after the bitterness?":

• Noticeable bitterness that dissolves quickly with strong huigan → a type many tea lovers enjoy, often described as having "a bitter base."
• Light bitterness, more sweetness → gentle and easy to drink.
• Heavy bitterness that doesn't dissolve → points deducted.

Why Does Astringency Dry Out Your Mouth?

The tea polyphenols in tea bind with proteins in your saliva and form a precipitate. The saliva that normally lubricates the mouth is "pulled away," so the mouth's surfaces become dry, tight, and rough. That puckering sensation is astringency. The dry, puckering feeling from red wine, persimmons, and unripe bananas works on a similar principle.

In good tea, astringency fades quickly, often accompanied by shengjin, so the mouth actually becomes more moist. Astringency that never fades, leaving the mouth drier with every sip, is "astringency that doesn't dissolve," and it costs points in tasting.

Does Heavy Bitterness and Astringency Mean Bad Tea?

Not necessarily; it depends:

• Young raw tea: Naturally retains large amounts of tea polyphenols and caffeine, so bitterness and astringency are normal. Many tea lovers believe young tea should have a certain amount of bitterness and astringency to leave room for transformation in storage.
• Regional character: Teas from some regions are known for a strong bitter base and fast huigan; bitterness is part of the style.
• Season: Summer tea usually has a higher polyphenol content and more noticeable bitterness and astringency; spring tea is relatively gentler.
• Brewing: Steep the same tea too long, and it becomes bitter and astringent. That's not the tea's fault.

The real flaws are "bitterness and astringency that don't dissolve," "astringency that leaves the mouth dry and won't fade," and "bitterness with off-flavors." If you simply dislike bitterness, choose ripe tea or raw tea that has aged for many years, where bitterness and astringency are much gentler; see Buying Pu'er for the First Time.

Do Bitterness and Astringency Change Over Time?

Yes. Over years of storage, the tea polyphenols in raw tea slowly oxidize and polymerize, the bitterness and astringency gradually soften, and the taste moves toward mellowness. Ripe tea goes through pile fermentation, which transforms a large share of the polyphenols, so its bitterness and astringency are clearly lower than young raw tea's. Details on these chemical changes are in How Tea Polyphenols Change.

Bitterness, Astringency, Region, and Season

Tea lovers often discuss regional styles in terms of bitterness and astringency. For example, tea from around Bulang Mountain in Menghai is often described as having a pronounced bitter base with huigan that comes fast and strong; the Bingdao area in Lincang is known for sweetness with light bitterness and astringency; and Yiwu is mostly described as gentle and low in astringency. These are experiential views from the tea world; there are big differences between villages and tree ages within the same region, so it's best not to generalize. Each region's flavor is covered in Regional Flavor Styles.

The effect of season is more consistent: Yunnan's rainy-season tea grows fast under strong sunlight and usually has a higher proportion of polyphenols, with more noticeable bitterness and astringency; spring tea grows slowly and accumulates more substance, so its bitterness and astringency are often gentler. Autumn tea has a higher aroma but a thinner taste.

Brewed Too Bitter and Astringent?

• Shorten the steeping time: Pour off the first few infusions after 5–10 seconds.
• Use less tea: Go from 8 g down to 5–6 g.
• Lower the water temperature slightly: Use 90–95°C (194–203°F) for young raw tea.
• Pour off completely: Don't let the tea sit with the leaves.

For more methods, read Too Bitter or Astringent?

FAQ

How do bitterness and astringency differ? Bitterness is a taste on the tongue, mainly from caffeine and similar compounds; astringency is a drying, tightening sensation in the mouth, mainly from tea polyphenols binding with salivary proteins.

What does it mean when bitterness dissolves? The bitter taste fades within seconds and turns into huigan; bitterness that stays on the tongue and won't fade is called bitterness that doesn't dissolve.

Why does astringency dry out my mouth? Tea polyphenols bind with proteins in saliva and precipitate, so the mouth loses its lubrication and feels dry, tight, and rough.

Does heavy bitterness and astringency mean bad tea? Not necessarily. Young raw tea naturally has them; what matters is whether they dissolve. Bitterness and astringency that don't dissolve, or astringency that leaves the mouth dry and won't fade, are the real flaws.