A good bowl of matcha is mostly technique. The powder matters — it sets the ceiling — but the gap between a smooth cup and a gritty one usually comes down to four unglamorous things: sifting, water temperature, ratio, and the shape of your wrist.
Sift, always
Matcha is milled fine enough to clump on contact with air. Those clumps will not whisk out; they break into smaller clumps and settle at the bottom of the bowl. Push a gram or two through a fine mesh sifter before any water touches it. It takes fifteen seconds and it is the single step most people skip.
Warm the bowl
Pour a little hot water into the chawan, swirl it, and tip it out. A cold bowl pulls heat out of a small volume of water quickly, and matcha whisked below temperature tastes thin. While the bowl is warm, dry it — the whisk needs a dry surface to move against.
Water at 70–80°C
Boiling water scalds matcha. The result is bitter in a flat, astringent way that no amount of whisking recovers. If you have no thermometer, boil and then wait three minutes, or pour once between two vessels. For ceremonial grades, stay near the lower end; the sweetness sits there.
Ratio
For usucha — thin tea, the everyday preparation — use 2 grams of matcha to roughly 60ml of water. Two heaped chashaku scoops is close enough. For koicha, thick tea, double the powder and halve the water; expect something closer to paint than to a drink, and use a ceremonial grade or don’t bother.
The wrist
This is where most people go wrong. The motion is not circular. Whisking in circles pushes powder to the edge and builds nothing. Instead, whisk briskly in a W or M shape, keeping the chasen just off the bottom of the bowl, using the wrist rather than the arm. Fifteen to twenty seconds of fast, light movement is enough.
You are aerating, not stirring. The foam that forms should be fine and even, with small bubbles rather than large ones. When the surface holds a soft, uniform crema, stop — over-whisking collapses it again. Finish by drawing the whisk slowly through the centre and lifting it straight up.
Caring for the chasen
Never wash a bamboo whisk with soap, and never leave it sitting in water. Rinse it in warm water immediately after use, work the prongs gently with your fingers to release trapped powder, and stand it on a whisk holder to dry in open air. A chasen kept this way lasts months of daily use. One left wet in a drawer grows mould and splits within weeks.
If it still tastes wrong
Bitter usually means the water was too hot. Flat and chalky usually means the matcha is old — once opened, a bag oxidises within four to six weeks, and colour is the tell. Fresh matcha is vivid, almost electric green. Matcha that has turned dull olive or yellowish is past its window, and no technique will bring it back.
Keep opened bags sealed and refrigerated, and buy in quantities you will actually finish.