Matcha colour: what it tells you and what it does not

Vivid green means the leaf was shaded and the powder is still fresh. Olive, khaki, or yellow-brown means it was shaded less, is old, or has been exposed to air and light. Colour is a reliable signal of shading and freshness — it is not a reliable signal of flavour, grind, or value for a milk drink.

Where the green comes from

Shading the tea plant for the weeks before harvest drives up chlorophyll, which is the green you see, and L-theanine, which is much of what you taste as umami. So colour and flavour are correlated, because the same production choice creates both.

That correlation is why colour works as a quick check. It is also why colour can mislead: anything that degrades chlorophyll after harvest — air, light, heat, time — dulls the colour without necessarily telling you how the leaf was grown.

What dull colour actually means

Old stock is the most common cause. Matcha fades steadily from the moment the bag is opened, and often before that if it was stored badly upstream.

Less shading is the second. Matcha from leaf that was shaded briefly or not at all is greener than sencha but noticeably duller than well-shaded tencha, and it will usually taste brisker and more astringent to match.

Neither is a safety problem. Both are a quality problem you will taste.

What colour does not tell you

Grind. A coarse, gritty powder can be perfectly green. Feel it between your fingers — powdered sugar rather than sand.

Whether it suits your drink. A magnificent green ceremonial matcha can still be the wrong purchase for a sweetened iced latte, where you are paying for delicacy that milk will erase.

Origin. Colour is about shading and freshness, not geography. A well-shaded, fresh matcha is vividly green wherever it was grown.

Checking colour properly

Look at the dry powder in natural light, not under warm café lighting, which flatters everything. Compare against another matcha if you have one — colour is much easier to judge side by side than alone.

Then check it in the drink you serve. A matcha that looks fine dry but turns grey-green in an iced latte is usually being under-dosed rather than being poor quality.

Keeping the colour you paid for

Air, light, heat, and time are what take it away. Keep the bag sealed, cool, and dark, decant a small working quantity, and buy about two months of usage rather than a year of stock. Matcha you bought cheaply and let fade is more expensive than the right amount of good matcha.