Matcha is made of tencha: tea leaf shaded for about three weeks or more before picking, steamed, dried flat without rolling, cleared of stems and veins, then ground on stone into a fine powder.
The Japan Tea Central Association writes this into its labelling standard, so powdered sencha or other green tea is green tea powder, not matcha.
Matcha is made of one leaf, tencha, and the leaf decides almost everything about the powder. The Japan Tea Central Association's labelling standard defines matcha as tencha ground fine in a tea mill. It defines tencha as leaf from gardens covered for about two to three weeks before picking, then steamed and dried without rolling. Two things in that sentence separate matcha from every other green tea, which are the shade before picking and the flat drying after it. Sencha, the everyday Japanese green tea, grows in open sun and is rolled into needles while it dries. Grind sencha and you get green tea powder, which is sharper, more bitter and duller in colour. It is useful in cooking, but it is not matcha, and a bag that only says "green tea powder" is usually telling you so.
The six steps from bush to tin
| Step | What happens | Why it matters |
|---|---|---|
| Shade | Bushes go under cloth or a reed canopy for roughly three weeks or more before picking | Keeps theanine in the leaf, so more umami and less bitterness, and deepens the green |
| Pick | The first spring shoots come off in late April and May, by hand in the best gardens | The first flush is the softest and sweetest leaf of the year |
| Steam | Leaf is steamed within hours of picking | Stops oxidation, so the leaf stays green |
| Dry flat | Leaf is blown apart and dried in a tall brick oven, never rolled | Gives tencha its flat flakes, which grind evenly |
| Sort | Stems and veins are cut away, leaving only the leaf blade | Stems and veins taste woody and grind poorly |
| Mill | Granite stones turn slowly, about 30 to 40 grams an hour per mill | Slow milling keeps the powder cool and very fine |
One stone mill makes about 30 to 40 grams of matcha an hour. That figure, from Tezumi's overview of how matcha is made, explains a good deal about the price of a tin. Eric Gower of Breakaway Matcha puts it the same way in his guide to production, where grinding 30 grams takes more than an hour. A tin of 30 grams is roughly an hour of one mill's work, after a season of shading and picking.
Shade first, then everything else
Shading is the step that makes matcha taste like matcha. The Global Japanese Tea Association explains that in sunlight the amino acid theanine breaks down into catechins, the bitter and astringent parts of the leaf. Under cover, more theanine stays, and theanine is what tastes savoury and sweet. With less light the plant also builds more chlorophyll, so the leaf turns a deeper green. Shading is done three ways. Kabuse lays black cloth directly on the bushes. Tana holds cloth on a frame above them. Honzu is the old method, a shelf of reed screens with straw spread on top, and it costs the most in money and labour. We wrote about the chemistry in more detail in why matcha is grown in the shade.
Why the leaf is dried flat
Rolling is what gives sencha its needle shape. It also bruises the leaf so its flavour comes out quickly in hot water. Matcha is not steeped, it is drunk whole, so rolling does nothing for it. Instead the steamed leaf is blown up a tall drying oven and comes out flat and crisp. Then it is cut and sieved to separate the blade of the leaf from stems and veins, which taste woody and do not grind well. What is left is tencha, small flat flakes of bright green. Producers often freeze tencha and grind it to order through the year, because ground matcha fades much faster than whole leaf.
What this means when you read a tin
- Look for the word matcha, not green tea powder. The second is a different product.
- Look for stone milled or stone ground. Tezumi argues in its piece on grades that matcha not ground on stone is arguably not matcha at all.
- Look for a harvest and a region. First flush, a prefecture or a town, and sometimes a cultivar or a farmer's name. These tell you more than any grade word.
- Look at the colour when you open it. Fresh matcha is a vivid jade green. Olive or yellowish powder has either been made from older leaf or has faded in storage.
To taste the difference, whisk it plain. Ippodo, a Kyoto tea house since 1717, gives its ratios as about 2 grams of matcha to 60 ml of water at 80°C for thin tea, and about 4 grams to 30 ml for thick tea. Plain water hides nothing, which is why we taste every matcha that way.
Questions
Is matcha just powdered green tea?
No. All matcha is green tea, but only tencha becomes matcha. Tencha is shaded before picking and dried flat without rolling. Grinding ordinary sencha gives green tea powder, which tastes sharper and looks duller.
What is tencha?
The leaf that matcha is ground from. It is shaded for weeks, steamed, dried in a tall oven without rolling, then sorted so only the soft leaf blade is left. It looks like small, flat, bright green flakes.
Is all matcha stone ground?
Traditional matcha is milled on granite stones, slowly, so the powder stays cool. Some cheaper matcha is ball-milled or jet-milled. Tezumi argues that matcha not ground on stone is arguably not matcha at all.
Does matcha have caffeine?
Yes. It is ground whole leaf from the tea plant, so you drink the leaf itself and the caffeine in it. How much depends on the tea and how much powder you use.
- Japan Tea Central Association, labelling standard for green tea (in Japanese)
- Tezumi, How Matcha is Made: An Overview
- Tezumi, Why ceremonial grade is meaningless
- Global Japanese Tea Association, Japanese Tea Cultivation
- Breakaway Matcha, How matcha is produced
- Ippodo Tea, Kanza product page with preparation ratios
