Why This Oolong Milk Tea (Trà Sữa Oolong) Is Worth Making at Home
If you have ever walked past a milk tea shop and been stopped cold by that warm, floral, almost buttery aroma drifting out the door — chances are it was an oolong base doing all the heavy lifting. Trà sữa oolong has earned its permanent spot at the top of Vietnamese milk tea menus for a very good reason: oolong’s layered, lightly oxidised character gives the drink a depth that plain black tea simply cannot match, and a natural sweetness that means you can go easy on the sugar without sacrificing satisfaction.
I have been testing milk tea recipes in my own kitchen for several years, and this one went through a lot of iterations before I was happy with it. The ratio below gives you a drink that is fragrant but not perfumey, creamy but not heavy, and sweet with a clean, lingering finish — exactly what a good trà sữa oolong should be.
Ingredients
- 16 g (about 4 tsp) high-quality oolong tea leaves — Jin Xuan (Milk Oolong) or Tie Guan Yin are ideal
- 300 ml filtered water, heated to 85–90 °C (185–194 °F)
- 200 ml whole milk (or oat milk for a dairy-free version)
- 60 ml heavy cream (30–35% fat), optional but recommended
- 3 tbsp (45 ml) simple syrup (1:1 sugar to water, cooled) — adjust to taste
- 1 pinch of fine sea salt
- Plenty of ice cubes to fill two 450 ml glasses
- Optional cream top: 80 ml heavy cream + 1 tbsp condensed milk + 1 pinch salt
How to Make Trà Sữa Oolong — Step by Step
Step 1: Warm Your Teapot or Vessel
Pour a small splash of hot water into your brewing vessel, swirl it around, and discard it. This simple step keeps the brew temperature stable from the very first second — a small habit that makes a noticeable difference in the final flavour.
Step 2: Measure and Brew the Oolong
Add 16 g of oolong leaves to your warmed vessel. Heat your filtered water to 85–90 °C — if you do not have a temperature-controlled kettle, bring water to a full boil and let it sit, uncovered, for about 2–3 minutes. Pour 300 ml of the measured water over the leaves and steep for exactly 4 minutes. Set a timer. Over-steeping oolong at this leaf-to-water ratio will introduce unwanted bitterness that no amount of milk can mask.
Step 3: Strain and Cool Slightly
Strain the tea through a fine-mesh sieve into a clean jug. Give it a moment to cool for 2–3 minutes — you want a hot concentrate, not a scorching one, before you add the dairy.
Step 4: Build the Milk Tea Base
Into the warm tea concentrate, stir in 3 tbsp of simple syrup, the pinch of sea salt, 200 ml of whole milk, and 60 ml of heavy cream. Stir gently — you are combining, not frothing. Taste and adjust the syrup at this point. The mixture should be noticeably fragrant and pleasantly sweet with a light, round body.
Step 5: Ice and Serve
Fill two 450 ml glasses generously with ice. Pour the milk tea base over the ice slowly so it chills as it hits. Leave about 2 cm of headspace if you plan to add a cream top.
Step 6 (Optional but Recommended): Make the Cream Top
Combine 80 ml of heavy cream, 1 tbsp of condensed milk, and a pinch of salt in a small jar or a cocktail shaker. Shake vigorously for 30–45 seconds until the mixture is slightly thickened — it should pour in a slow ribbon, not whip into stiff peaks. Spoon or pour it gently over the back of a spoon onto the surface of each drink. Sip without a straw first: the contrast between the salted cream and the sweet floral tea underneath is the whole point.
Practical Tips for the Best Results
- Tea leaf quality matters more than anything else here. Because oolong is the star, a cheap or stale tea will give you a flat, papery drink. Look for tea with a clearly marked harvest date and buy from a reputable tea shop or importer.
- Do not skip the salt. Even a small pinch in the base and the cream top rounds out sweetness and amplifies the floral notes. This is the same principle behind salted caramel — it works.
- Whole milk vs. oat milk: Whole milk gives you a richer mouthfeel and plays better with oolong’s floral character. A good barista-blend oat milk (higher fat content) is a solid dairy-free substitute. Avoid skimmed milk — the drink will taste thin and watery.
- Make a larger batch of tea concentrate and refrigerate it (without the milk) for up to 48 hours. Cold-brew in the fridge overnight (8–12 hours) using cold water for a naturally sweeter, less astringent concentrate — just double the leaf amount.
- Simple syrup tip: For a more interesting flavour, infuse your syrup with a vanilla pod or a strip of pandan leaf while it cools. It adds a layer of fragrance that pairs wonderfully with Jin Xuan oolong.
Variations
Brown Sugar Oolong Milk Tea
Replace the simple syrup with 3 tbsp of brown sugar syrup (simmer dark brown sugar with water until dissolved) and drizzle extra syrup down the inside walls of the glass before adding ice. The caramel depth works beautifully against the floral tea notes.
Taro Oolong Milk Tea
Blend 60 g of cooked and cooled taro with 100 ml of the milk tea base until completely smooth, then strain and add back to the drink. The earthy, nutty taro bridges oolong’s floral notes in a way that feels surprisingly elegant.
Cold Brew Oolong Milk Tea
Use 32 g of oolong leaves steeped in 400 ml of cold, filtered water overnight in the fridge (8–12 hours). Strain, combine with milk and a touch less sweetener (cold brew oolong is naturally sweeter), and serve over ice. This is the smoothest, least astringent version of the drink — great for people who find hot-brewed tea occasionally sharp.
Oolong Dirty Matcha
Brew the oolong base as directed, pour over ice and milk, and finish with a single shot of espresso or a teaspoon of strong matcha dissolved in a tablespoon of warm water floated on top. Unusual, but genuinely delicious — the earthiness of matcha or espresso cuts through the cream beautifully.
Sparkling Oolong Milk Tea
Reduce the milk to 100 ml, skip the cream, and top each glass with 100 ml of chilled sparkling water added gently just before serving. Light, refreshing, and unexpectedly elegant for a summer afternoon.
FAQ
What type of oolong tea is best for trà sữa oolong?
Jin Xuan (also sold as Milk Oolong or Golden Daylily) is the most popular choice for milk tea because it carries a natural, creamy floral note that blends seamlessly with dairy. Tie Guan Yin works well if you prefer a slightly more roasted, complex profile. Avoid heavily roasted dark oolongs (like Da Hong Pao) for this recipe — their earthy, charcoal notes tend to get muddled rather than elevated by milk.
Why does my oolong milk tea taste bitter?
The two most common culprits are water that is too hot (above 90 °C denatures delicate oolong compounds quickly) and steeping for too long. Stick strictly to 85–90 °C water and a 4-minute steep time with this leaf ratio. If you find the drink is still a touch astringent, try reducing the leaves to 12 g and extending the steep by 30 seconds — every tea is slightly different depending on the harvest and processing.
Can I make this recipe ahead of time?
Yes. Brew the tea concentrate and mix it with the sweetener, but keep it separate from the milk until you are ready to serve. The unsweetened or sweetened tea concentrate (without milk) keeps well in an airtight container in the refrigerator for up to 48 hours. Once you add milk, aim to drink it within a few hours for the best flavour and texture.
Is there a lower-sugar option?
Absolutely. Start with 1 tbsp of simple syrup instead of 3, taste, and add more in small increments. Jin Xuan oolong has a noticeable natural sweetness on its own, especially in the cold-brew variation, so many people find they need significantly less added sugar than they expect. You can also use a small amount of condensed milk in place of both the cream and the syrup — it is sweeter per tablespoon but adds dairy and richness at the same time, so you need less of everything overall.
Can I use tea bags instead of loose leaves?
You can, though the flavour will be noticeably less complex. If using tea bags, look for pyramid-style bags that contain whole or large-leaf oolong rather than the fine dust found in standard flat bags. Use 3–4 bags for this recipe and steep for 3 minutes rather than 4, as the greater surface area extracts faster and can turn bitter quickly.
