What matcha actually is

Matcha is not simply green tea turned into powder. It is a particular leaf, grown in a particular way, processed to a particular point, and then milled slowly enough that the powder does not cook itself.

Shade

For roughly three weeks before harvest, the bushes are covered. Deprived of full light, the plant makes more chlorophyll and holds on to more L-theanine instead of converting it into catechins. That is the whole trick behind the colour and the savoury, almost broth-like sweetness. Unshaded leaf, however carefully milled, gives you a flat, grassy, bitter powder.

Steam, not pan

Japanese green tea is steamed within hours of picking. The steam kills the enzymes that would otherwise oxidise the leaf. Chinese green teas are usually pan-fired, which is why they taste toasted rather than marine. Matcha is steamed, dried, then de-stemmed and de-veined — the remaining leaf flesh is called tencha.

Stone

Tencha is milled on granite wheels at around 30–40 grams an hour. Slow means cool: heat destroys aroma and turns the powder dull. A ball mill can produce the same fineness in minutes, and you can taste the difference — flatter, slightly stale, a hint of hay.

What this means for you

• Colour is a first signal, not proof. Vivid jade suggests shade and freshness; olive or khaki suggests old, unshaded or ball-milled powder.
• Matcha is a perishable food, not a pantry staple. Oxygen and light are the enemies. Buy small, use fast.
• "Ceremonial" is a marketing word with no legal definition. Origin, harvest date and cultivar tell you far more.

The next part is the method: how to make a bowl that shows what you paid for.