Vietnamese Oolong Tea: Taste, Origins and Brewing Guide
Vietnamese oolong tea is a partially oxidised tea grown and produced in Vietnam — a country far better known internationally for green tea and coffee than for oolong.
Yet in the Central Highlands, particularly around Bao Loc, Di Linh, Cau Dat and Da Lat, a distinctive oolong industry has developed.
Depending on the cultivar and production method, Vietnamese oolong can be light and floral, smooth and creamy, rich with ripe-fruit notes or deep and roasted. This range makes it one of Vietnam’s most varied and rewarding tea styles.
In this guide, we explore where Vietnamese oolong comes from, how it is produced, what it tastes like, how to brew it and what to look for when choosing a high-quality loose-leaf tea.
What Is Vietnamese Oolong Tea?
Vietnamese oolong is tea grown and processed in Vietnam using partial oxidation.
Green, oolong and black tea all come from the same plant, Camellia sinensis. What separates them is largely how the freshly harvested leaves are handled after picking.
Green tea is heated relatively early to limit oxidation. Black tea is allowed to oxidise much more fully. Oolong covers the broad range between them.
Yet oolong is not simply a halfway point between green and black tea. Its character is shaped through withering, leaf agitation, controlled oxidation, heat fixation, rolling and drying. Some styles also receive an additional roast.
These decisions give producers considerable control over the finished tea. One oolong may be fresh, floral and pale in the cup, while another may be darker, warmer and more full-bodied.
Where Is Vietnamese Oolong Tea Grown?
Lam Dong is one of Vietnam’s most important tea-producing regions.
Located in the Central Highlands, the province contains several distinct growing areas at different elevations. Bao Loc and Di Linh lie on the Di Linh Plateau, while Cau Dat and Da Lat occupy higher ground farther north.
Bao Loc has a long association with tea cultivation and processing. Its mild highland climate, rainfall and established tea industry make it an important centre for both traditional Vietnamese tea and newer oolong styles.
For tea drinkers accustomed to seeing China and Taiwan dominate conversations about oolong, Lam Dong offers another origin worth discovering.
ZAVYO’s Black Oolong is sourced from Tang Vinh An, a tea producer based in Dambri, Bao Loc. Knowing the producer and processing location provides greater transparency than a general “Product of Vietnam” description.
The Development of Oolong in Lam Dong
Oolong originated outside Vietnam, but producers in Lam Dong have built their own industry around the style.
Modern oolong production in Lam Dong has been strongly influenced by Taiwanese tea cultivars and processing traditions. Cultivars of Taiwanese origin, including Jin Xuan and Si Ji Chun, are now grown in the region.
Vietnamese producers create several expressions of oolong, from lightly oxidised floral teas to darker, fuller styles suited to a stronger traditional cup or modern milk-tea preparation.
Vietnamese oolong should therefore be understood neither as an ancient native style nor as a simple copy of Taiwanese tea. It is a more recent chapter in Vietnam’s tea story, shaped by outside influences but developed within the country’s own growing regions.
Oolong Cultivars Grown in Vietnam
A cultivar is a cultivated variety of the tea plant selected for particular growing or sensory characteristics.
Producers in Lam Dong work with several oolong cultivars. Two names commonly encountered are Jin Xuan and Si Ji Chun.
Jin Xuan or Kim Tuyen
Jin Xuan is a Taiwanese cultivar also known as Taiwan Tea No. 12. In Vietnam, it is commonly called Kim Tuyen.
It is often associated with a smooth texture and naturally creamy or softly floral character. However, the cultivar does not guarantee one particular flavour and should not automatically be confused with artificially flavoured “milk oolong”.
Si Ji Chun or Tu Quy
Si Ji Chun is commonly translated into English as Four Seasons or Four Seasons Spring. In Vietnam, it is generally known as Tu Quy.
It is an aromatic and productive cultivar used for oolong production in several Asian tea-growing regions.
Tang Vinh An lists both Kim Tuyen and Tu Quy among the oolongs it produces in Bao Loc. The exact cultivar used for ZAVYO Black Oolong has not yet been confirmed, so neither should be assigned to the product without further information.
How Vietnamese Oolong Tea Is Made
Production methods vary between producers, cultivars and intended styles, but a typical oolong process follows several essential stages.
1. Harvesting
Fresh tea shoots are collected and transported for processing.
The maturity and condition of the leaves influence the final cup, so producers try to avoid unnecessary compression or damage before controlled processing begins.
Tang Vinh An’s production description emphasises keeping harvested leaves cool and ventilated before moving them promptly to the processing facility.
2. Outdoor Withering
The leaves may first be exposed briefly to outdoor air or sunlight.
This is withering rather than complete drying. The leaves lose part of their moisture, become more pliable and begin developing new aromatic compounds.
3. Further Withering
The leaves continue to wither under more controlled conditions.
Moisture moves gradually through each leaf while its texture, aroma and internal chemistry begin to change.
4. Tossing and Gentle Bruising
The leaves are gently tossed, shaken or mechanically agitated.
This lightly bruises parts of the leaf, particularly around the edges, exposing more of its internal compounds to oxygen and helping to develop the aromas and colours associated with oolong.
5. Controlled Oxidation
The bruised leaves are allowed to oxidise for a controlled period.
Oxidation is the correct term for this stage. Although some translated tea descriptions call it “fermentation”, conventional oolong does not rely on microbial fermentation in the way that genuinely post-fermented teas do.
The producer monitors changes in aroma, colour and texture before deciding when to stop the process.
6. Heat Fixation
Heat is applied once the desired degree of oxidation has been reached.
This deactivates most of the enzymes responsible for oxidation, helping preserve the intended character of the tea.
7. Rolling and Shaping
The leaves are rolled or shaped according to the intended style.
Rolling influences their final appearance and how they release flavour during brewing. Some oolongs are tightly rolled, while others have a looser or more twisted form.
8. Drying
The shaped leaves are dried to reduce their remaining moisture and stabilise the tea for storage.
Some oolongs receive additional baking or roasting, which can create deeper toasted, nutty or caramel-like notes. Drying and roasting, however, are not the same process, and not every oolong is roasted.
What Does Vietnamese Oolong Tea Taste Like?
There is no single flavour shared by every Vietnamese oolong.
The taste depends on the cultivar, growing area, harvest and production method. Oxidation and roasting can transform the finished tea considerably.
Lighter Vietnamese oolongs may offer:
- Floral aromas
- Fresh vegetal notes
- A smooth or creamy texture
- Gentle natural sweetness
- A pale golden liquor
More oxidised or darker styles may offer:
- Ripe-fruit or honeyed notes
- Caramel-like sweetness
- Toasted grain or nuts
- A fuller body
- A deeper amber or reddish-brown liquor
Depending on the style, oolong can range from delicate and floral to deeply roasted, while whole-leaf teas may continue to change in aroma and texture over successive infusions.
Black Oolong from Bao Loc
Produced by Tang Vinh An in Bao Loc, Black Oolong is a darker, full-bodied style selected for drinkers who prefer a stronger cup.
ZAVYO’s tasting notes describe it as follows:
Aroma: Rich and warm with caramel-like notes
Taste: Full-bodied, gently astringent and naturally sweet
Finish: Deep, rounded and lingering
Liquor: Clear reddish-brown
The name “Black Oolong” does not mean that the product is black tea. It remains an oolong, but its darker liquor and fuller character distinguish it from lighter green or floral styles.
It can be enjoyed on its own, softened with a splash of milk or prepared as an oolong milk tea.
How to Brew Vietnamese Oolong Tea
There is no single temperature that suits every Vietnamese oolong.
Light, floral oolongs may respond better to moderately hot water, while darker and more robust styles may require water close to boiling. Leaf size, rolling, oxidation and roasting all influence the best brewing method.
Always begin with the instructions supplied for the individual tea.
How to Brew Black Oolong
For a classic cup:
- Tea: 8 g
- Water: 250 ml
- Temperature: 100°C
- Time: 3–5 minutes
Place the leaves in a teapot or spacious infuser and add freshly boiled water. Brew for 3–5 minutes, then strain completely.
Enjoy without milk or add a small splash according to taste.
These instructions are specific to Tang Vinh An Black Oolong; lighter oolong styles may call for different temperatures and infusion times.
How to Make Oolong Milk Tea
For a richer drink:
- Tea: 10 g
- Water: 200 ml
- Temperature: 100°C
- Time: 5 minutes
- Milk: Approximately 50–100 ml
Brew the tea for five minutes and strain completely.
Add approximately 50–100 ml of milk according to your preferred strength and texture. Serve hot or pour over ice. Sweetener is optional.
Brewing Oolong with Multiple Short Infusions
Many whole-leaf oolongs can also be prepared using more leaf, less water and a series of short infusions.
This method allows the aroma, texture and finish to develop gradually as the leaves open. The ideal ratio, temperature and number of infusions will depend on the individual tea.
For Tang Vinh An Black Oolong, the classic 8 g per 250 ml method remains the recommended starting point.
Does Vietnamese Oolong Tea Contain Caffeine?
Yes. Vietnamese oolong is made from Camellia sinensis and naturally contains caffeine.
The amount in a cup varies according to:
- The cultivar and leaf material
- The quantity of tea used
- The water temperature
- The brewing time
- The number of infusions
It is therefore inaccurate to describe every oolong as either high or low in caffeine.
Those who are particularly sensitive to caffeine may prefer a smaller serving, a shorter infusion or tea earlier in the day. Oolong is not caffeine-free, even when brewed at a lower temperature.
How to Choose Vietnamese Oolong Tea
A trustworthy description should tell you more than simply “Vietnamese oolong”.
Look for:
- A clearly identified country and region of origin
- The producer or processing facility, where known
- The cultivar, if it has been confirmed
- A complete ingredient list
- Clarity about whether flavouring has been added
- Realistic tasting notes
- Instructions created for the individual tea
- Secure packaging that protects the leaves from air and moisture
Be cautious when a seller makes extremely precise claims about altitude, cultivar, harvest or oxidation without explaining where the information came from.
Transparency is more valuable than a long list of unverified premium-sounding details.
How to Store Vietnamese Oolong Tea
Store loose-leaf oolong in a tightly sealed container away from:
- Direct sunlight
- Heat
- Moisture
- Coffee, spices and other strong aromas
Tea absorbs surrounding odours easily. A cool, dry cupboard is usually more suitable than an open shelf in a warm kitchen.
Close the packaging promptly after each use. There is generally no need to refrigerate an opened everyday oolong unless the producer provides specific storage instructions.
Frequently Asked Questions
What is Vietnamese oolong tea?
Vietnamese oolong is partially oxidised tea grown and processed in Vietnam. Many examples are produced in Lam Dong, including the tea-growing areas around Bao Loc, Di Linh, Cau Dat and Da Lat.
What does Vietnamese oolong taste like?
Its flavour can range from light and floral to rich, fruity, caramel-like or roasted. The final character depends on the cultivar, growing conditions, oxidation and any additional roasting.
Where is Vietnamese oolong grown?
Lam Dong in Vietnam’s Central Highlands is one of the country’s principal oolong-producing regions. Bao Loc, Di Linh, Cau Dat and the area surrounding Da Lat are all associated with tea cultivation, although their elevations and growing conditions differ.
How should Vietnamese oolong be brewed?
Follow the instructions for the individual tea. Lighter oolongs may suit moderately hot water, while darker styles may require water close to boiling. ZAVYO Black Oolong is brewed with 8 g of tea, 250 ml of water at 100°C and an infusion time of 3–5 minutes.
Can Vietnamese oolong be brewed more than once?
Many whole-leaf oolongs can be infused several times, although the result depends on the tea and brewing method. Short multiple infusions generally use a higher proportion of leaves and less water.
Does Vietnamese oolong contain caffeine?
Yes. All conventional oolong made from Camellia sinensis naturally contains caffeine. The amount in the cup varies with the leaves, portion size, water temperature and brewing time.
Is Black Oolong the same as black tea?
No. Black Oolong remains an oolong tea. The name indicates a darker style or product classification, but it does not make the tea fully oxidised black tea.
Discover Vietnamese Oolong
Vietnamese oolong offers far more variety than a single flavour or brewing style.
Light oolongs can be fresh and floral, while darker teas bring greater body, warmth and depth. Understanding the origin and production method makes it easier to choose a tea that suits the way you genuinely enjoy drinking it.
Vietnamese oolong is also a reminder that some of Asia’s most interesting teas can be found beyond the origins most people already know.
Exploring tea by region, producer and processing style opens up a much bigger world than simply choosing between green, black and oolong.
That spirit of discovery is at the heart of ZAVYO: finding distinctive teas across Asia and bringing their origins, character and stories into the cup.
Prefer a deeper, fuller cup? Discover Black Oolong from Bao Loc — a rich Vietnamese oolong with warm caramel-like notes and a naturally sweet, lingering finish.