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When we call a tea “good,” we are judging three things at once: the taste on the tongue (bitter, astringent, umami, sweet), the aroma in the nose (floral, fruity, roasted…), and the mouthfeel in the mouth (body, smoothness, returning sweetness). And behind every flavour is a specific molecule.
The interactive flavour wheel below sorts tea’s flavours into eight families. Pick a tea and the wheel highlights its typical notes; hover any segment to see the compound responsible:
选一种茶，风味轮高亮它的典型风味；悬停任一色块，看对应的呈味 / 呈香物质。
风味轮分类与代表化合物综合自茶叶风味化学研究；同一描述常由多种化合物共同造成，此处为主要对应、非唯一。
Switch between green, oolong, black and dark tea and you’ll see it directly: green tea concentrates in green, umami and bitter-astringent notes; oolong fans out into floral and fruity; black tea shifts to sweet-floral and body; dark tea settles into woody-aged and mellow. This is the flavour projection of their different crafts.
L2 · Deep Dive1. The substances behind taste
Tea’s “taste” (the gustatory part) is mainly set by these water-soluble substances:
| Taste | Main substances | Note |
|---|---|---|
| Bitter | caffeine, some catechins | caffeine is the main bitter source, and adds lift |
| Astringent | catechins (esp. galloylated) | bind mouth proteins to give a drying grip |
| Umami | theanine and other amino acids | core of freshness and returning sweetness; softens bitterness |
| Sweet | soluble sugars, some amino acids | mellow sweetness and “hui gan” |
| Body | theaflavins, thearubigins, theabrownins, pectin | oxidation/fermentation products that build body |
Green tea has the most catechins, so it is brisk but bitter-astringent; in black tea catechins are oxidised into theaflavins and thearubigins, lowering astringency and raising body; dark tea forms theabrownins, the least astringent and most mellow. (See leaf chemistry.)
2. The substances behind aroma
Tea aroma comes from trace volatile compounds — hundreds identified so far. They arise by three broad routes:
- Native to the leaf (terpenes): e.g. linalool (sweet floral) and geraniol (rose), the mainstays of floral aroma.
- Enzymatic / stress-induced: wounding and enzymatic release during bruising and rolling generate floral-fruity compounds like cis-jasmone, nerolidol, indole and methyl jasmonate (see oolong zuoqing).
- Heat-formed: Maillard reactions and pyrolysis during fixation, roasting and drying create pyrazines (chestnut, roasty) and other baked notes.
| Representative compound | Aroma type | Common in |
|---|---|---|
| Linalool / geraniol | sweet floral / rose | black, oolong, white |
| cis-Jasmone / indole / jasmine lactone | heady floral (jasmine) | oolong, scented tea |
| β-ionone | violet / fruity | oolong, black |
| Nerolidol | woody floral | oolong, dark |
| (Z)-3-hexenol | grassy / fresh | green, white |
| Dimethyl sulfide | seaweed / shaded | steamed green, gyokuro |
| Pyrazines | chestnut / roasty | pan-fired green, roasted oolong |
A single note usually arises from several compounds; the table gives the main correspondence for understanding, not the only source.
3. The character of the six tea types
- Green: fresh and brisk with returning sweetness, a touch of green bitterness. High catechins and amino acids; aromas of green leaf, chestnut (pan-fired) or seaweed (steamed).
- White: delicate, sweet and downy, soft with little astringency. Amino acids and sugars stand out; light sweet-floral aroma; mellows with age.
- Yellow: mellow-sweet and gentle with low astringency, often a “toasty” note. Yellowing tempers green tea’s rawness.
- Oolong: richly floral-fruity, full and smooth with a long sweet finish. Partial oxidation balances polyphenols and amino acids; the most aromatic type, with fire notes in roasted styles.
- Black: sweet-floral, fruity and malty; bold and brisk. Theaflavins give briskness and brightness, thearubigins give body; Assam is malty, Darjeeling muscatel.
- Dark (ripe pu-erh): mellow and smooth, aged and woody, very low astringency. Dominated by theabrownins, with growing woody, medicinal and fungal notes over age.
4. How to “taste” a tea
Professional evaluation looks at five points: appearance, liquor colour, aroma, taste, infused leaf. For everyday drinking, three steps: first smell (dry leaf, lid, liquor, empty-cup aromas); then taste (let the liquor coat the mouth and feel the layers and balance of bitter/astringent/umami/sweet); finally sense the returning sweetness and throat feel. The value of the flavour wheel is to give these elusive impressions a shared, comparable vocabulary.
The flavour code: how composition becomes “taste”
Connecting compounds to the senses — why each tea tastes the way it does:
Why is green tea brisk?
high amino acids (umami) + high catechins (grip)
= fresh and brisk, clear returning sweetness
Key compoundstheanine, EGCG
Why is white tea delicate-sweet?
high amino acids & sugars + very light oxidation
= soft sweetness, downy aroma
Key compoundstheanine, soluble sugars
Why is yellow tea mellow, not grassy?
men-huang tempers harshness + builds sweet notes
= mellow-sweet with a toasty note
Key compoundssoluble sugars, pheophytin
Why is oolong so aromatic yet smooth?
zuoqing creates hundreds of aromatics + partial oxidation cuts astringency
= "fragrant for seven steeps"
Key compoundslinalool, nerolidol, indole, jasmine lactone
Why is black tea full and sweet?
thearubigins (body) + lower catechins (less astringent) + Maillard (sweet)
= smooth and sweet, bright red liquor
Key compoundstheaflavins, thearubigins
Why is dark tea aged and smooth?
theabrownins + microbial aged aroma + caffeine binding cuts astringency
= mellow and smooth, growing aged aroma
Key compoundstheabrownins, gallic acid
See also
- The Science of each craft — how flavour is generated during processing
- Leaf chemistry · Brewing — how composition and brewing shape flavour
References
- Recent Advances in Volatiles of Teas. Molecules / PMC, 2018. https://pmc.ncbi.nlm.nih.gov/articles/PMC6273888/
- Methyl Jasmonate-Induced Changes of Flavor Profiles During the Processing of Green, Oolong, and Black Tea. Frontiers in Plant Science, 2019. https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2019.00781/full
- (R)-Linalool is a key indicator of aroma quality of a distinctive black tea. Industrial Crops & Products, 2025. https://www.sciencedirect.com/science/article/pii/S0926669025000524
- Tea Polyphenols: Tastes and Tea Choices. Tea Guardian. https://www.teaguardian.com/tea-health/tea-polyphenols-tastes-tea-choices/
Flavour descriptions and compound mappings are synthesised from tea flavour-chemistry research; exact levels and perceptions vary with cultivar, craft, origin and brewing.