Brew Thai black tea, the tea behind Thai iced tea (cha yen), with water just off the boil, about 95–100 °C (203–212 °F), and steep it 3–5 minutes; for an iced-tea concentrate, use double the leaf and steep about 5 minutes. Thai botanical infusions such as lemongrass, roselle and bael fruit take the same near-boiling water for 5–10 minutes, while green, jasmine and oolong leaves want cooler water: roughly 70–80 °C for green tea and 85–95 °C for rolled oolong.
Thai Tea Brewing Temperature and Steep Time Chart
| Tea type | Water temperature | Steep time | Amount per 8 fl oz cup | Notes |
|---|---|---|---|---|
| Thai black tea, hot cup | 95–100 °C (203–212 °F) | 3–5 minutes | 2–3 g (1 heaped teaspoon) | Malty and brisk; turns bitter past about 5 minutes |
| Thai iced tea concentrate (cha yen) | 100 °C (212 °F), full boil | About 5 minutes | 4–6 g (double a hot cup) | Sweeten while hot; cool before icing |
| Green and jasmine green tea | 70–80 °C (158–176 °F) | 2–3 minutes | About 2 g | Boiling water makes it bitter and astringent |
| Thai oolong (rolled leaf) | 85–95 °C (185–203 °F) | 3–5 minutes | 2–3 g | Rolled leaves re-steep 2–3 times |
| Lemongrass, roselle, bael fruit, ginger | 90–100 °C (194–212 °F) | 5–10 minutes | 1–2 teaspoons (about 2 g); 5–10 g of bael slices | No tea leaf: long steeps add strength, not bitterness |
| Butterfly pea flower | 90–100 °C (194–212 °F) | 5–10 minutes | 1–2 g | Longer steep, deeper blue; lime juice turns it purple |
| Chrysanthemum and other dried flowers | 90–95 °C (194–203 °F) | 3–5 minutes | 4–6 whole flowers | Light and honeyed; flowers re-steep 1–2 times |
| Cold brew, any of the above | Cold water, in the fridge | 6–12 hours for tea leaf; 4–8 hours for botanicals | About twice the hot amount | Smoother and lighter than a hot brew |
What temperature should the water be for Thai tea?
For Thai black tea, use water at or just off a full boil, 95–100 °C (203–212 °F). Thai tea is a fully oxidized black tea, usually Ceylon-style or Assam, and it needs that heat to draw out its malty body and deep color. Water well below 90 °C gives a thin cup that fades once milk and ice go in.
Some Thai teas are green, jasmine-scented or oolong, and boiling water scorches them: brew green and jasmine at 70–80 °C (158–176 °F) and rolled oolong at 85–95 °C (185–203 °F). No thermometer? Pour just-boiled water into a cold cup, wait about 20 seconds, then pour it over the leaves; that brings it to roughly 80–85 °C.
How long should you steep Thai tea?
Steep Thai black tea 3–5 minutes for a hot cup: three for a lighter, brisker tea, five for a fuller, maltier one. Past about five minutes the leaf gives up more tannin than flavor and the cup turns bitter, so if you want it stronger, add more leaf rather than more time.
Green and jasmine tea need only 2–3 minutes and rolled oolong 3–5. Botanical infusions are more forgiving at 5–10 minutes; with no tea leaf in them, a longer steep deepens flavor and color rather than bitterness.
How do you brew Thai tea for iced tea?
Thai iced tea starts from a concentrate about twice as strong as a hot cup: 4–6 g of Thai black tea per 8 fl oz of water at a full boil, steeped about 5 minutes, strained and sweetened while hot. Doubling the leaf, not the time, is what lets the tea stand up to ice and condensed milk.
Some cooks, our recipe included, simmer the leaves a few minutes first for extra body, and some recipes for commercial Thai tea mixes steep much longer, letting sugar and milk cover the bitterness. Either way, strength comes mostly from the amount of leaf. Cool the concentrate before adding ice, or the drink turns watery. Our Thai iced tea recipe has the full method, and our Assam Thai tea leaves are a traditional base for it.
Strength sets the caffeine too: roughly 30–70 mg in a home-brewed 8 fl oz cup of Thai black tea, 60–130 mg in a double-strength 16 fl oz cafe glass (Thai tea caffeine guide).
What temperature should Thai herbal and botanical infusions be brewed at?
Most Thai botanical infusions want water at or near a boil, 90–100 °C (194–212 °F), for 5–10 minutes. Lemongrass, roselle, bael fruit and ginger are dried stalks, calyces, fruit slices and roots that release flavor slowly, and none contains tea leaf, so a long, hot steep will not turn them bitter the way it does black tea.
Delicate flowers want water just off the boil rather than boiling: chrysanthemum is at its best at 90–95 °C (194–203 °F) for 3–5 minutes. Cover the cup while botanicals steep, since lemongrass loses its citrus aroma with the steam. Our 15-botanical Thai infusion brews at 90–95 °C for 5–10 minutes. None of these infusions contains caffeine.
What are the most common Thai tea brewing mistakes?
Most disappointing cups come from water that is too hot for the leaf, water too cool for it, or a steep that runs too long. Bitter, weak and odd-tasting tea each have a simple fix, and none needs more than a kettle and a timer.
- Boiling water on green or jasmine tea. The cup turns bitter and astringent. Cool the water to 70–80 °C first.
- Water that has cooled too far for black tea or botanicals. The result is thin and flat. Pour straight off the boil.
- Steeping black tea longer to make it stronger. Past about five minutes it turns bitter. Use more leaf instead.
- Too little leaf for iced tea. A normal-strength brew tastes watery once the ice melts. Double the leaf.
- A cold teapot. It drops the water temperature at once. Rinse the pot with hot water first.
- A flat or soapy taste. This often comes from hard or alkaline tap water, or soap left in a teapot, infuser or cup, rather than the tea. Use filtered water and rinse teaware well. Over-long steeps, especially of strongly scented teas, can also taste soapy.
Can you cold-brew Thai tea?
Yes. Use about twice the usual amount of leaf in cold water and leave it in the fridge for 6–12 hours for black tea, or 4–8 hours for most botanicals. Cold brewing draws out less tannin, so the result is smoother and less bitter than a hot brew.
It is also lighter, so classic Thai iced tea with condensed milk is better from a hot-brewed concentrate; cold brew suits unsweetened Thai tea or botanicals over ice.
Frequently Asked Questions
What water temperature is best for Thai tea?
Thai black tea, the base of Thai iced tea, brews best with water just off the boil, about 95–100 °C (203–212 °F). Green and jasmine Thai teas need 70–80 °C (158–176 °F), rolled Thai oolong 85–95 °C, and Thai botanical infusions such as lemongrass and roselle 90–100 °C.
How long should you steep Thai tea?
Steep Thai black tea 3–5 minutes for a hot cup, and about 5 minutes with double the leaf for an iced-tea concentrate. Past about 5 minutes it turns bitter, so add leaf rather than time for a stronger brew. Thai botanical infusions can steep 5–10 minutes.
Why does my Thai tea taste bitter?
Thai tea usually turns bitter because it steeped too long: black tea left much past 5 minutes releases extra tannin. Green or jasmine Thai tea also goes bitter in water that is too hot. For a stronger cup without bitterness, use more leaf and keep black tea to 3–5 minutes.
How much Thai tea should you use per cup?
For a hot 8 fl oz cup of Thai black tea, use 2–3 g of loose leaf, about 1 heaped teaspoon. For Thai iced tea, brew a concentrate with roughly double that, 4–6 g per 8 fl oz of water, so the tea still tastes strong after ice and condensed milk go in.
What temperature should Thai herbal tea be brewed at?
Most Thai herbal teas, including lemongrass, roselle, bael fruit, ginger and butterfly pea flower, brew at 90–100 °C (194–212 °F) for 5–10 minutes. Delicate dried flowers such as chrysanthemum do better just off the boil, at 90–95 °C for 3–5 minutes. Thai herbal teas contain no tea leaf, so they have 0 mg of caffeine.
This article covers preparation and culinary information only. Temperatures, times and amounts are starting points; teas and blends vary, so adjust to taste.
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