What water for matcha
80°C, and lightly mineralized water. How to achieve this without a thermometer, and what water hardness really changes in taste.
L'essentiel
Matcha is two grams of powder to seventy milliliters of water.
Water therefore represents the overwhelming majority of what you drink — and yet
it's the parameter that is looked at last.
Two things matter: its temperature, and its minerality.
Temperature: 80 °C
The number is well known, the reason less so.
Green tea contains two families of compounds with opposing behaviors. The
amino acids, responsible for sweetness and roundness, are extracted at
low temperatures. Catechins, responsible for bitterness and
astringency, need heat.
At 80 °C, you get sweetness with just enough bitterness to give
character. At 95 °C, catechins dominate everything and the bowl becomes harsh.
It's as simple as that, and it's the primary cause of bitterness — the subject is
detailed in
Why your matcha is bitter.
How to achieve it without a thermometer
Wait. Boiling water left for two minutes in an open kettle
drops to around 80 to 85 °C. This is the simplest method.
Transfer. Each transfer from one container to another causes a loss of
about ten degrees. Two transfers get you approximately where you need to be.
Visual cue. Around 80 °C, fine bubbles form at the bottom of the
saucepan without rising in a chain. Large bubbles mean it's already too late.
Cold addition. A tablespoon of cold water in 70 ml of boiling
water lowers the temperature by approximately 10 °C.
Depending on the preparation
Usucha, the classic bowl — 80 °C. The reference.
Koicha, thick matcha — 75 °C. The dosage is more concentrated, so it's more
sensitive to bitterness.
Matcha latte — 80 °C also for the base. The milk, however, is heated
separately to 60-65 °C, never boiling.
Mizudashi, cold matcha — cold water directly, 5 to 10 °C. The extraction
of catechins is minimal: the result is very mild. An excellent entry point
if bitterness puts you off.
Minerality: what really changes
This is the part almost no one talks about, and it's measurable.
Water that is too hard, loaded with calcium and magnesium, reacts with the
compounds in the tea. The color becomes dull, the foam holds less well, and the
taste is flattened. If your matcha is consistently disappointing despite a good
temperature and grade, your water is a serious suspect — especially if you already use our Ceremonial Matcha.
Conversely, water that is too pure — reverse osmosis, demineralized — yields a
flat, lifeless result. A minimum of minerals is needed to carry the aromas.
The optimal range is around 30 to 80 mg/L of dry residue, which is lightly
mineralized water. In Japan, the water is naturally very soft, and the entire
tea culture has developed around this characteristic.
In practice
Tap water. It is suitable in most regions. Two caveats: chlorine, which masks
aromas, and hardness in limestone areas. Let it
rest for an hour in the open air — most of the chlorine evaporates.
Filtered pitcher water. Good compromise. The cartridge removes chlorine and some
limescale. Change it regularly: a saturated cartridge releases.
Low-mineral bottled water. The best result, provided you
read the label and aim for a low dry residue. Highly mineralized waters
should be avoided for tea.
Pure reverse osmosis water. Too neutral. If this is your only option, the result will be
correct but lack depth.
The two-bowl test
If you want to decide at home, it's simple. Prepare two identical bowls,
same matcha, same dosage, same temperature — one with tap water, the other with
low-mineral water.
The color difference is often visible even before tasting. If it's obvious to you,
your water is a lever. Otherwise, don't think about it anymore and concentrate
on the temperature.
Frequently asked questions
Can boiled water be reused multiple times?
Technically yes, but it degasses and gives a flatter result. Prefer
freshly heated water.
Sparkling water?
No. Acidity changes the color and breaks the aromatic profile.
Should the bowl be preheated?
It's a real plus: a cold bowl causes the temperature to drop by several degrees
at once. Rinse it with hot water, wipe dry, prepare according to the full method.
Does milk replace water?
Never on first contact. The powder should always meet water first,
otherwise the milk proteins create irreversible lumps.
The complete gesture, step by step: The Ritual.
