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WELLNESSWEEK
A Long‑Standing Misconception
Many people assume that green tea comes from green tea trees, black tea from black tea trees. The neatly arranged shelves in supermarkets naturally lead to an illusion: different coloured teas come from different kinds of trees.
That’s not true at all.
There is no such thing as a “green tea tree” or a “black tea tree” in nature. All teas—green, white, yellow, oolong, black, and dark tea—come from the same plant: the tea plant (Camellia sinensis). What turns a freshly plucked leaf into six completely different teas is not the variety of the tree, but the processing method.
And at the heart of that processing is fermentation.
More precisely, it is the “oxidation” of polyphenols in the tea leaves, driven by enzymes and oxygen. The degree of fermentation ranges from 0% to 100%, and every step along that spectrum determines the tea’s colour, aroma, flavour, and health properties.
The six types of tea are, in essence, a battle of fermentation.
First, Let’s Clarify: What Exactly Is Tea “Fermentation”?
Before we dive into the six types, let’s get one fundamental question straight: is tea “fermentation” the same as the fermentation used in winemaking or bread‑making?
The answer is no.
Winemaking and bread‑making rely on microorganisms—yeast and lactic acid bacteria—that convert sugars into alcohol or lactic acid. Tea “fermentation,” more accurately called “oxidation,” is a chemical reaction catalysed by polyphenol oxidase.
Fresh tea leaves are rich in polyphenols and polyphenol oxidase. When the leaf cells are damaged (through rolling or crushing), the enzyme comes into contact with the polyphenols, triggering oxidation. The polyphenols gradually polymerise into theaflavins (bright yellow), thearubigins (red), and theabrownins (brown). The deeper the fermentation, the darker the liquor becomes.
This process is exactly like a sliced apple slowly turning brown when exposed to air—the same principle. The only difference is that the Chinese mastered it, controlled it, and turned it into an art.
The degree of fermentation determines the tea’s base colour:
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No fermentation → chlorophyll dominates → green
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Light fermentation → xanthophyll emerges → yellow
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Semi‑fermentation → brown pigments emerge → green‑brown
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Full fermentation → red pigments emerge → red
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Post‑fermentation → microorganisms participate → dark brown to black
The lower the fermentation, the closer the tea tastes to the fresh plant—fresh, crisp, with a natural vegetal note. The higher the fermentation, the deeper and richer the aroma and the sweeter, more mellow the flavour.
Green Tea (Unfermented, 0%): Locking Spring’s Greenness into the Cup
Fermentation level: 0%
Green tea has the lowest fermentation of all—in fact, none at all.
As soon as the fresh leaves are plucked, they are immediately tossed into a hot pan or wok at high heat. This process is called fixation (or “kill‑green”). The high heat instantly deactivates polyphenol oxidase. With the enzyme dead, oxidation is halted, and the green colour is “locked” into the leaves.
A cup of green tea—from the dry leaves to the liquor to the spent leaves—is entirely green. That’s its signature.
Flavour‑wise, green tea is all about “freshness” and “crispness.” It carries a vegetal aroma—grassy, nutty, or chestnut‑like—with a clean, refreshing taste and a pleasant, lingering sweetness.
In terms of health benefits, because it undergoes no fermentation, green tea retains the highest levels of polyphenols (especially EGCG), preserving over 85% of the catechins and caffeine found in fresh leaves. Among all teas, green tea has the strongest antioxidant capacity. But for that very reason, it is also the most cooling in nature and can be more stimulating to the digestive system.
Famous examples: West Lake Longjing, Bi Luo Chun, Huangshan Maofeng.
White Tea (Slightly Fermented, 5%–10%): No Frying, No Rolling—Just Let the Sun Work Slowly
Fermentation level: 5%–10%
White tea is the simplest—and laziest—tea of all: no fixation, no rolling.
Fresh leaves are spread out on bamboo mats and left to wither naturally. Sunlight and gentle breezes slowly carry away the moisture over about 60 hours. During this time, the leaves’ own enzymes work slowly and subtly. When the leaves are about 70–80% dry, they are gently finished with a low‑heat drying.
Without frying or rolling, white tea preserves the most original form and flavour of the leaf.
Flavour‑wise, white tea is about “fresh sweetness” and “downy aroma.” Because it hasn’t been subjected to high heat, the fine white hairs (trichomes) on the leaf surface remain intact, giving the liquor a unique “floating fuzz” appearance. The taste is delicately sweet, with a hint of “sun‑kissed” warmth.
Health‑wise, white tea retains a good amount of polyphenols, but is milder than green tea and less irritating to the stomach.
Famous examples: Bai Hao Yin Zhen (Silver Needle), Bai Mu Dan (White Peony), Shou Mei.
Yellow Tea (Lightly Fermented, 10%–20%): Green Tea with an Extra “Sweltering” Step
Fermentation level: 10%–20%
Yellow tea is like “green tea’s classmate”—its production process is almost identical: plucking, fixation, rolling. But yellow tea has one extra critical step: sweltering (or “yellowing”).
After fixation and rolling, the leaves are wrapped in paper or piled together and left in a warm, humid environment for a period. During this “sweltering” phase, chlorophyll partially degrades and polyphenols oxidise slightly. The leaves gradually turn from green to yellow‑green, then to yellow. The breakdown of chlorophyll allows yellow pigments like xanthophyll to emerge.
Flavour‑wise, yellow tea has less bitterness than green tea and more sweetness and mellowness. The grassy note disappears, replaced by sweet, chestnut‑like, or orchid‑like aromas.
Health‑wise, yellow tea sits between green and black teas—it is milder than green tea and less irritating.
Famous examples: Junshan Yinzhen, Mengding Huangya, Huoshan Huangya.
Yellow tea is the rarest and least produced of the six types. Because the sweltering process is tricky to control, making yellow tea is labour‑intensive and not particularly rewarding. If you’ve ever had yellow tea, you’re already in a small minority.
Oolong Tea (Semi‑Fermented, 15%–70%): The Most Complex and Varied Tea
Fermentation level: 15%–70% (the widest range)
If green tea is “locking spring into a cup,” then oolong is “letting the leaves find the perfect balance in the dance between enzymes and oxygen.”
Oolong’s processing is the most complex, time‑consuming, and skill‑demanding of all teas.
After plucking, the leaves are first sun‑wilted, then enter the most critical step: tumbling (or “shaking”). During tumbling, the edges of the leaves are bruised and damaged, triggering localised oxidation—the leaf edges turn red while the centre remains green, creating oolong’s signature “red edge, green centre.”
Once the desired degree of oxidation is reached, high‑heat fixation stops the process. But this isn’t done in one go—it requires repeated cycles of shaking, resting, and shaking again, allowing oxidation to proceed in fits and starts. The more refined the craft, the more layered the oolong’s flavour.
Oolong’s fermentation range is huge: lightly oxidised Baozhong is only about 10%, Tieguanyin is around 50–60%, and Da Hong Pao or Fenghuang Dancong can reach 70%.
Flavour‑wise, oolong is the most aromatic tea family. Floral, fruity, honeyed, roasted—different cultivars, oxidation levels, and roasting techniques yield entirely different aroma profiles. It offers the freshness of green tea and the richness of black tea at the same time.
Health‑wise, oolong combines some of green tea’s antioxidant power with some of black tea’s gentleness. It is neutral in nature and suitable for most people’s daily consumption. Its polyphenol content sits between green and black teas; catechins are partly converted into theaflavins and thearubigins while some remain intact.
Famous examples: Tieguanyin, Da Hong Pao, Fenghuang Dancong, Dongding Oolong.
Our White Peach Oolong belongs to the oolong family—a semi‑fermented oolong base, paired with real dried white peach slices. The natural floral‑fruity layers of oolong blend perfectly with the sweet, refreshing note of white peach. It’s not as cooling as green tea, nor as warming as black tea—a tea that suits any constitution and any time of day.
Black Tea (Fully Fermented, 70%–90%): The Polyphenols’ Grand Transformation
Fermentation level: 70%–90%
Black tea works on the opposite logic to green tea—no fixation, rolling first, then full oxidation.
After withering, the leaves are rolled. Rolling thoroughly ruptures the leaf cells, bringing polyphenol oxidase and polyphenols into full contact. Then, under suitable temperature and humidity, fermentation proceeds, and the polyphenols are heavily oxidised. Within tens of minutes to a few hours, the leaves turn from green to red, and the spent leaves become completely reddish‑brown.
During this process, polyphenols polymerise into theaflavins (bright yellow) and thearubigins (red). Theaflavins are the main contributors to the “brightness” of black tea liquor and also add strength and freshness to the taste. Thearubigins provide depth and mellowness.
Flavour‑wise, black tea is about “sweetness” and “mellow richness.” Most polyphenols have been transformed, so bitterness and astringency are greatly reduced. In their place are fruity, floral, and honeyed notes, with a gentle, sweet, and smooth mouthfeel.
Health‑wise, black tea is very low in irritants and is extremely stomach‑friendly. Its caffeine content is relatively high, but thanks to the buffering effect of theaflavins, its stimulating effect is more gradual and sustained than coffee’s.
Famous examples: Zhengshan Xiaozhong (Lapsang Souchong), Keemun, Dianhong.
Our two flavoured black teas build on the gentle nature of fully fermented black tea:
Lychee Rose Black Tea—a black tea base with real dried lychee pieces and rose petals. The rich, warming character of black tea combines with lychee’s natural sweetness and rose’s floral elegance. It’s mild, stomach‑friendly, and especially suited for women or anyone in need of a comforting warm drink.
Ginger Black Tea—black tea with real dried ginger slices. Ginger contains various active compounds that support digestion and circulation, while black tea is naturally warming and gentle on the stomach. Together they create a rich, comforting brew, perfect for those with a cooler constitution, cold hands and feet, or simply when the weather turns chilly.
Dark Tea (Post‑Fermented, 100%): The “Friend of Time” with Microbial Help
Fermentation level: 100% (post‑fermentation)
Dark tea is fundamentally different from the other five types: its fermentation does not rely on the tea leaves’ own enzymes, but on microorganisms.
After fixation and rolling, the leaves are piled up, sprinkled with water, and covered. In the warm, humid environment, large numbers of microorganisms (mainly fungi) begin to multiply. This process is called piling (or “wet‑piling”). During piling, microbial metabolic activity degrades polyphenols and generates new flavour compounds. Polyphenol content can drop by 22–45%, while gallic acid content increases significantly. At the same time, microbial fermentation produces a wealth of flavour precursors that lay the foundation for ageing.
Flavour‑wise, dark tea is about “aged” and “mellow.” After piling and subsequent ageing, the tea develops a rich array of microbial metabolites. The taste is smooth, thick, and carries a distinctive aged aroma. Over time, the quality and flavour continue to evolve.
Health‑wise, dark tea has extremely low levels of irritating substances and is the gentlest on the stomach—it is the most warming of all teas.
Famous examples: Ripened Pu‑erh, Anhua Dark Tea, Liubao Tea.
At a Glance: The Six Tea Types
| Tea Type | Fermentation Type | Level | Key Process | Characteristics |
| Green | Unfermented | 0% | Fixation | Clear liquor, green leaves |
| White | Slight | 5%–10% | Withering | Silvery down, pale liquor |
| Yellow | Light | 10%–20% | Sweltering/Yellowing | Yellow leaves, yellow liquor |
| Oolong | Semi‑ | 15%–70% | Tumbling/Shaking | Red edge, green centre |
| Black | Fully | 70%–90% | Rolling + Oxidation | Red leaves, red liquor |
| Dark | Post‑ | 100% | Piling | Dark oily leaves, deep brown liquor |
How to Choose the Right Tea for You
Understanding the battle of fermentation ultimately answers one practical question: Which tea should I drink?
There is no “best tea”—only the tea that best suits you. It comes down to three factors: your digestive tolerance, your flavour preferences, and your drinking occasions.
If you have a strong stomach and want maximum antioxidants: go for green or white tea.
Lowest fermentation means the most polyphenols retained. But they are cooling in nature and can irritate the stomach if drunk on an empty stomach. Best enjoyed an hour after a meal.
If you want something mild, everyday, and adaptable: go for oolong.
Semi‑fermented, neutral in nature, moderate in stimulation. Rich in aroma and layered in flavour—not too cooling, not too warming. Suitable any time of day.
If you have a sensitive stomach, tend to feel cold, or prefer a sweet, mellow taste: go for black or dark tea.
Full or post‑fermentation means very few irritants and maximum stomach‑friendliness. They are warming, comforting, and perfect for mornings or colder days.
If you’re after something rare and different: try yellow tea.
The smallest production and hardest to find. Its taste falls between green and black teas—sweet and smooth.
The Fermentation Philosophy in a Cup
From 0% to 100%, fermentation is a game of time and a contest of craftsmanship.
The same leaf, because of different fermentation levels, transforms into six completely different teas. This is the ultimate understanding and utilisation of a single leaf—adding nothing, merely controlling the degree of oxidation to give one plant six entirely different expressions.
In this sense, the six tea types are not six different plants, but six different “times.” Green tea is time that locks spring in place; black tea is time that allows polyphenols to fully transform and recombine; dark tea is time that lets microbes work slowly.
Next time you pick up a cup of tea, take a moment to think: what is the fermentation level of this tea? What oxidation journey did it go through? Why is it green, yellow, red, or brown?
Fermentation is the soul of tea. And every sip you take is the outcome of this battle.
Where Do Our Teas Stand on the Fermentation Spectrum?
After reading the above, you can probably answer this yourself:
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White Peach Oolong → Semi‑fermented, standing between green and black teas. Mild, layered, and suitable for everyone.
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Lychee Rose Black Tea → Fully fermented—polyphenols have transformed into theaflavins and thearubigins. Gentle, stomach‑warming, sweet and mellow.
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Ginger Black Tea → Also a fully fermented black tea base, paired with real ginger slices. It adds an extra layer of warming power beyond plain black tea.
Three teas, three different fermentation positions. They aren’t plucked from three different trees—they come from the same leaf, processed differently to reach different endpoints. Every cup you choose is the result of a complete fermentation journey.