The caffeine in oolong tea lands in the moderate middle: on average roughly 30 to 50 mg per 8 oz (240 ml) cup, which is less than a mug of brewed coffee, usually a little under black tea, and a touch more than most green teas. Those are rough, variable figures, though — the real amount in your cup swings with the specific leaf, how much of it you use, how hot your water is, and how long you steep.
Because oolong is a whole family of teas — anything from barely oxidised, green-leaning styles to dark, roasted ones — its caffeine content covers a band rather than one tidy number. So yes, oolong tea has caffeine, and the honest answer to "how much" is "somewhere in a range." Below is a practical, hedged look at what to expect and what nudges the figure up or down. For what oolong actually is and where it comes from, see our guide to oolong tea; here we stay narrowly on the caffeine question.
How much caffeine in oolong tea per cup: the rough number
Most references put an 8 oz cup of oolong somewhere around 30 to 50 mg of caffeine, with a lot of them clustering near the high 30s. Treat that as a ballpark rather than a lab reading. Published oolong caffeine content figures vary widely because they come from different leaves, brewed for different times, at different temperatures, by different people — and caffeine is water-soluble, so the way you brew moves the number as much as the leaf itself does.
It also helps to know that caffeine is not a marker of "strength" you can taste. A dark, toasty roasted oolong can feel bold and full on the palate while carrying a similar amount of caffeine to a light, floral one. Flavour and caffeine simply are not the same axis, which is why guessing from taste rarely works.
Oolong vs coffee, black tea and green tea caffeine
The quickest way to place oolong is against the drinks you already know. On the classic oolong vs coffee caffeine question, coffee usually wins by a wide margin — very roughly twice as much per cup, sometimes more. Against tea, oolong tends to sit just below black tea and just above most greens, though the ranges overlap enough that any given cup can break the pattern.
| Drink (rough, per 8 oz / 240 ml cup) | Approximate caffeine |
|---|---|
| Brewed coffee | ~80–100 mg |
| Espresso (single ~1 oz shot) | ~60–75 mg |
| Black tea | ~40–70 mg |
| Oolong tea | ~30–50 mg |
| Green tea | ~20–45 mg |
| White tea | ~15–30 mg |
| Decaf coffee | ~2–5 mg |
Read that table as a set of fuzzy bands, not exact readings — every figure here is an average that hides a lot of spread. For a fuller cross-drink breakdown with sodas, energy drinks and more, see our roundup of caffeine in drinks compared. And if you are still wondering whether tea contains caffeine at all, our explainer on whether tea has caffeine covers the basics for every leaf type.
What changes the caffeine in your oolong
The single biggest reason two cups of "the same" oolong can differ is that caffeine is pulled out of the leaf by hot water over time. Change the brewing and you change the number. The main levers:
- Leaf grade and how many buds and tips it has. Caffeine concentrates in the youngest growth, so teas made with more tender buds and tips tend to carry more of it than those made from older, larger leaves.
- How much leaf you use. More leaf per cup means more caffeine, plainly. A heaped gongfu-style dose in a small pot extracts differently from a modest pinch in a big mug.
- Water temperature. Hotter water pulls caffeine faster. A near-boiling steep extracts more than a cooler one over the same time.
- Steep time. Longer steeps keep dissolving caffeine, so a five-minute cup will generally have more than a one- or two-minute cup of the same tea.
- Re-steeps. Oolong is famous for giving several infusions from one measure of leaf, and each successive steep hands over progressively less caffeine as the leaf is depleted. The first steep is usually the most caffeinated; later ones are gentler.
If you want to actually get the most out of those multiple infusions, our guide to brewing oolong tea walks through leaf ratios, temperatures and timing in detail.
Does roasting lower the caffeine in oolong? (mostly a myth)
A common belief is that a dark, heavily roasted oolong must have less caffeine than a light, greener one — the reasoning being that heat "burns off" caffeine. In practice this is largely a myth. Caffeine is fairly stable at the temperatures used to roast tea, so a roasted oolong and a greener one made from comparable leaf tend to have broadly similar caffeine content. Roasting changes aroma, colour and mouthfeel far more than it changes caffeine.
There is a small, hedged caveat: some tasters and vendors report that heavily roasted oolongs seem to release their caffeine a little more slowly, which can make the same cup feel mellower even when the total is much the same. Whether that is a real extraction effect or partly perception is hard to pin down, so it is best not to lean on "roasted equals decaf" — it is not. If a lower-caffeine cup is the goal, how you brew matters more than how the leaf was roasted.
How to get less caffeine from your oolong
Since brewing does most of the work, a few small adjustments can meaningfully trim the caffeine in a cup of oolong — without switching teas:
- Steep for a shorter time. Pulling the leaf out sooner leaves more caffeine behind in the wet leaf. A quick steep is the easiest single lever.
- Use cooler water. Dropping below a rolling boil slows extraction, so a lower-temperature brew of the same leaf usually ends up a little lighter on caffeine.
- Lean on later steeps. Because re-steeps give progressively less caffeine, a second or third infusion is naturally gentler than the first.
- Try a quick rinse. Some drinkers do a short first steep, discard it, and drink the following infusions. This removes some caffeine, but only a modest fraction — it is a nudge, not a way to "decaffeinate" tea, so treat any claim that it strips most of the caffeine with skepticism.
- Use a little less leaf. Fewer grams in the pot simply means less caffeine available to extract.
Who might want to keep an eye on it
For most people an ordinary cup or two of oolong is an unremarkable amount of caffeine, comfortably below a couple of coffees. A few situations are worth a bit more attention: if you are sensitive to caffeine, drinking oolong late in the day, or pregnant or breastfeeding and watching your total intake. In those cases the safest move is to count oolong toward your overall daily caffeine rather than treating tea as "free," and to lean on the shorter-steep and later-steep tricks above.
Responses to caffeine vary a lot from person to person, and this is general information rather than medical advice — if you have specific concerns about caffeine and your health, pregnancy, or sleep, ask your own healthcare provider. For a wider look at what a moderate daily amount looks like, it helps to treat oolong as one contributor to your total intake rather than an exception to it.
The bottom line
Oolong tea is a genuinely moderate-caffeine drink: figure on roughly 30 to 50 mg in a cup, less than coffee, usually a little under black tea, and a shade above most greens — but hold that number loosely, because the leaf and especially your brewing can push it either way. If you want more energy from the same leaf, brew it hotter and longer; if you want less, steep it short, keep the water cooler, and let the later infusions do the pouring. Either way, the caffeine in oolong tea is easy to dial once you know which levers to pull.