Brewing / Water
Tea is mostly water.
About 99% of what's in the cup is water. The leaf is the seasoning. Most people spend on the leaf and ignore what they're seasoning.
The opening principle
Lu Yu, who wrote the first book about tea in the 8th century, ranked water sources from best to worst. Mountain spring at the top. River water in the middle. Well water last. The reasoning was about dissolved minerals — too few and the cup is flat, too many and the cup is muddied. Modern tap water sits in the wide middle of that spectrum and the spectrum still applies.
What the minerals do
Pure distilled water makes flat tea. The cup has no body, no structure, no finish — the polyphenols in the leaf need calcium and magnesium ions to bind with. Heavy mineral water makes muddy tea. Calcium scale forms on the surface, delicate aromatics get masked, the cup reads cloudy. The sweet spot is somewhere between 30 and 100 ppm of total dissolved solids — bottled spring water sits comfortably in that range, most municipal supplies sit above it, and reverse osmosis water sits below it.
A practical hierarchy
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Bottled spring water
Crystal Geyser, Volvic, Mountain Valley. 60–150 ppm range. The reference cup. Expensive if you drink a lot of tea — worth it for high-grade Japanese greens and ceremonial matcha, optional everywhere else.
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Filtered tap water
A Brita pitcher or under-sink carbon filter strips the chlorine without stripping the minerals. Good enough for daily drinking. The single best return per dollar in any tea setup.
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Tap water, run cold and fresh
If your tap water tastes clean unfiltered, it'll make clean tea. Run it cold every time — water that's been sitting in the kettle since yesterday has lost its dissolved oxygen and brews flat.
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Distilled or RO water — don't
Strip-mined of minerals. Flat cup with no structure. A common mistake among people new to tea who assume purer means better.
Temperature — the part people get wrong
Boil it once. Don't re-boil.
Re-boiled water tastes flat for the same reason day-old water does — the dissolved oxygen has been driven off and the cup loses brightness. Boil what you need, use what you boiled, dump the rest. The British habit of topping up the kettle from yesterday's water is a small crime against any leaf delicate enough to notice.
Target temperatures, by leaf
| Type | Target | If no kettle |
|---|---|---|
| Black | 212°F | Full rolling boil. |
| Pu-erh | 212°F | Full rolling boil. |
| Oolong (roasted) | 205°F | Boil, rest 30s. |
| Oolong (rolled) | 195°F | Boil, rest 90s. |
| Green | 175°F | Boil, rest 3 min, or pour 1:1 with cold. |
| Matcha | 175°F | Same as green. |
| White | 185°F | Boil, rest 2 min. |
| Herbal / tisane | 212°F | Full rolling boil. |
The kettle that solves this
You can do all of the above with a regular kettle and a kitchen timer. You can also buy a Fellow Stagg EKG or a Bonavita gooseneck and dial the exact temperature for the leaf in front of you. The first time you brew a sencha at 170°F instead of 200°F you'll understand the argument for variable temperature. Greens stop tasting like grass. Whites start tasting like honey. Lighter oolongs unfold instead of bracing.
House note
The shortest path to better tea isn't a more expensive tin. It's filtered water, the right temperature, and not letting the leaf sit a second too long.