Water temperature changes more about a cup of Japanese green tea than anything else you can adjust. It is also the easiest thing to get wrong, because the habit of using boiling water comes from black tea and nobody tells you it is different here.
What temperature actually changes
Tea leaves contain catechins, which give astringency, and amino acids, which give sweetness and umami. Hot water pulls the catechins out quickly. Cooler water pulls the amino acids out and leaves most of the catechins behind.
That is the whole trick. Cooler water brings out sweetness and depth, hotter water brings out more astringency. Neither is wrong. Hot water simply gives you a different tea from the same leaf.
Every tea on this site lists the temperature, the time and the amount of leaf we recommend for it. Treat those as a starting point rather than a rule. Change one thing at a time, taste what it does, and keep what you like. Some people prefer a gyokuro brewed warmer than any book would suggest, and there is nothing to correct about that.
Getting to 70 °C without a thermometer
Boiling water loses roughly 10 °C each time you pour it into another cup at room temperature, and roughly 5 °C for every minute it stands in an open cup.
So: boil, pour into a cup, wait a minute, pour onto the leaf. That lands you in the seventies.
If you make tea every day, a kettle with temperature settings is the single most useful thing you can buy. A yusamashi is the traditional answer and it is more pleasant to use, but it does the same thing.
Per type
| Tea | Water | Why |
|---|---|---|
| Gyokuro | 50 to 60 °C | Shaded leaf is dense in amino acids. Hot water wastes that |
| Shincha | 65 to 70 °C | Young leaf, delicate. Heat flattens it |
| Sencha, deep steamed | 70 to 75 °C | Fine leaf extracts faster, so it is often brewed a little shorter |
| Sencha, standard | 75 to 80 °C | The middle ground |
| Tamaryokucha | 75 °C | Rounder leaf, forgiving |
| Kukicha | 80 °C | Stems need more heat to give anything up |
| Genmaicha | 85 to 90 °C | The rice needs heat |
| Bancha | 90 °C | Larger leaf, low in catechins to begin with |
| Hōjicha | 95 °C | Roasted. There is almost nothing bitter left to extract |
If it tastes wrong
Bitter or drying: water too hot, or steeped too long. Drop 10 °C first, then take fifteen seconds off.
Thin or watery: not enough leaf. Add a gram before you add time.
Flat, no aroma: the tea may be old or has been open too long. That is a storage problem, not a brewing one.
How to store tea → or shop all tea →