How to Brew Black Tea: Temperature, Time and Milk
Brew black tea at 93 to 100°C for 3 to 5 minutes. Times for bags, whole leaf and Lapsang, plus what the evidence says on milk and re-boiled water.
Key takeaways
- Use one teabag, or one rounded teaspoon of loose leaf, per cup.
- A teaspoon of loose leaf varies a lot with the cut, so weigh it once.
- Black tea is fully oxidised. During oxidation the catechins in the leaf polymerise into theaflavins and thearubigins, the compounds behind black tea's colour, body and dry, brisk finish.
- The UK Tea & Infusions Association says to add milk after brewing and, with a bag, to take the bag out first.
- The UK Tea & Infusions Association advises against re-boiled water, which it says is low in oxygen and dulls the flavour.
Short answer. Black tea wants water at or just off the boil, about 93 to 100°C, and a steep of three to five minutes. Bags and broken leaf are done at three to four minutes; whole leaf and smoky Lapsang Souchong can take four to five. Pull the leaf out when it tastes brisk but before it turns dry, and add milk after brewing unless you have a reason not to.
Black tea temperature and time
| Tea | Water | Time | Source |
|---|---|---|---|
| Most black tea, bags and blends | 90 to 98°C | 3 to 4 minutes | UK Tea & Infusions Association |
| Whole-leaf black such as Assam | 94 to 99°C | 3 to 5 minutes | Tea Association of the USA, as quoted in trade guides |
| Lapsang Souchong | 90 to 98°C | 4 to 5 minutes | UK Tea & Infusions Association |
| Harney & Sons black teas | Boiling water | 4 to 5 minutes | Harney & Sons |
| Darjeeling first flush | 80 to 90°C | 2 to 3 minutes | See the Darjeeling flush guide |
| Darjeeling second flush | 85 to 95°C | 2 to 4 minutes | Same |
Use one teabag, or one rounded teaspoon of loose leaf, per cup. The ISO 3103 laboratory standard for tea tasting uses 2 g per 100 ml of boiling water for six minutes. That recipe exists so that professionals can compare samples, not because it makes the nicest cup, and tea-trade writers often recommend five.
How much leaf per cup
| Guide | Dose |
|---|---|
| UK Tea & Infusions Association | One teabag or one rounded teaspoon of loose leaf per cup |
| Harney & Sons | One teaspoon per cup, or one sachet per two cups |
| ISO 3103 tasting standard | 2 g per 100 ml |
A teaspoon of loose leaf varies a lot with the cut, so weigh it once. Fine broken leaf packs far more into a spoon than rolled whole leaf does. If a cup tastes thin after the right time, the dose is the thing to change.
Fixing a cup that is off
| What you taste | Likely cause | Change |
|---|---|---|
| Dry, puckering, bitter | Steeped too long, or too much leaf for the water | Shorten the steep by 30 to 60 seconds |
| Watery, pale | Too little leaf, or a steep that is too short | Add leaf first, then time |
| Flat, dull | Re-boiled or stale water, or old leaf | Fresh water for every pot; UKTIA warns against re-boiling |
| Rough with milk | Brewed too strong for milk | Shorten the steep or use a little less leaf |
What oxidation does to the cup
Black tea is fully oxidised. During oxidation the catechins in the leaf polymerise into theaflavins and thearubigins, the compounds behind black tea's colour, body and dry, brisk finish. That is why black tea survives near-boiling water, and why a long steep tips from brisk into coarse so easily: those larger compounds keep coming out of the leaf, and astringency builds with them.
What the clock does
Three minutes gives a lighter, more aromatic cup. Five gives depth and more astringency. A 2025 Foods study that brewed black and other teas at 80°C and 100°C for 2, 5 and 10 minutes found that longer brewing raised caffeine and L-theanine, and that cup-size black tea bags gave more caffeine than loose leaf (39 against 24 mg per 200 ml). A likely reason for the second finding is that bags hold small particles, which infuse fast.
The practical rule is to match the clock to the cut of the leaf. Short for bags and CTC, longer for whole leaf, and shorter again for delicate Darjeeling. If it tastes dry and thin at the same time, you steeped too long. If it tastes watery, add leaf, not minutes.
Milk: first or last?
The UK Tea & Infusions Association says to add milk after brewing and, with a bag, to take the bag out first. The Royal Society of Chemistry argued in 2003, in a piece reported by the press, that milk should go in first because milk proteins can denature when drops meet tea hotter than about 75°C, which it said gives a stale taste. Both camps are repeating a position more than a measurement, so choose by taste. If the tea is made in a pot, either order works. If you add milk last, you also see the colour and can judge strength.
Should you re-boil the kettle?
The UK Tea & Infusions Association advises against re-boiled water, which it says is low in oxygen and dulls the flavour. Boiling only as much as you need, measured with the mug, avoids the issue and saves energy.
A starting recipe
- Fill the kettle with fresh cold water, enough for your mug.
- Boil it. Warm the mug or pot.
- Add one bag or one rounded teaspoon of leaf per cup.
- Pour on water near the boil.
- Set a timer for three minutes. Taste. Go to four or five only if the cup is thin.
- Remove the leaf. Add milk if you take it.
Questions people ask
How long should black tea steep?
Three to four minutes for most bags and blends, four to five for Lapsang and some whole-leaf teas.
Should black tea be made with boiling water?
Close to it. UKTIA gives 90 to 98°C, and trade guides give 94 to 100°C. Delicate Darjeeling is the exception.
Why is my black tea bitter?
Almost always a long steep or too much leaf for the water. Shorten the time first.
Does milk change how the tea should be brewed?
Milk softens astringency, so a slightly stronger base works. If you add milk, brew for the shorter end of the range and check the strength.
Why does my black tea go cloudy as it cools?
That cloudiness is called tea cream. A 2022 study of black tea infusions found the cream held more caffeine, polyphenols, theaflavins and thearubigins than the clear liquid it separated from, so it is the same material that gives the tea its colour and body, coming out of solution as the cup cools. It is not a fault. It matters mainly for iced tea, and cooling the brew more slowly or brewing it weaker reduces it.
Can I resteep black tea?
Whole-leaf black tea can usually be steeped again, at least twice for a tea like Keemun, and each cup is softer and often fruitier than the first. Add a minute or two to the second steep, or pour off the first before it turns bitter. Teabag fannings give very little the second time, because they are made to release everything at once.
Related
Sources
- UK Tea & Infusions Association: seven tips for the ultimate brew.
- Harney & Sons: how to brew black tea, and the Bunn tea basics brochure quoting Tea Association ranges.
- ISO 3103 / BS 6008, tea tasting method, as described on Wikipedia.
- Ayakdaş G, Ağagündüz D. L-theanine and caffeine in tea infusions with different fermentation degrees and brewing conditions. Foods 2025. doi:10.3390/foods14132313
- Qin C et al. Comparison of the supernatant and cream from black tea infusion. Food & Function 2022. doi:10.1039/d2fo00707j
- Zhang S et al. Using comprehensive two-dimensional liquid chromatography to unveil and mitigate the bidirectional quantification biases of non-volatile compounds in Chinese black tea processing. Food Chemistry: X 2026. doi:10.1016/j.fochx.2026.103991
- Resteeping: Rare Tea Company, its Keemun page and Artful Tea.
- Royal Society of Chemistry advice on tea, 2003, reproduced.