Grades, origin & product choice
Stone-Milled Matcha: Why the Milling Method Matters
Milling is the last step in making matcha: dried, destemmed tencha leaf is ground into powder. Stone milling is the traditional method: slow, cool and gentle, it produces a fine, even powder, and that is why it costs more per kilo than faster methods. Machine-milled matcha is still matcha, and milling is only one factor in quality. But it affects texture, and texture is something your guests notice straight away.
How matcha is milled
Before milling, the leaf has already been shaded, steamed, dried and sorted to remove stems and veins (the full sequence is in how matcha is made). What is left, tencha, is flaky and light. It needs to become a powder fine enough to suspend in water when whisked.
MAFF describes the leaf being ground in a stone mortar, and JETRO describes stone milling as the traditional method. JETRO also notes that some matcha is now milled by machine and is still classified as matcha. So the milling method is a production choice, not part of the definition.
Stone milling vs faster methods
| Stone milling | Faster mechanical milling | |
|---|---|---|
| How it works | Two grooved granite stones turn slowly; leaf is fed in at the centre and powder emerges at the edge | High-speed grinding, for example with blades or air-driven mills |
| Speed | Slow; small quantities per mill | Much faster, larger volumes |
| Heat | Low, because the stones turn slowly | Can be higher; depends on the equipment and how it is run |
| Particle shape and size | Fine and relatively even | Varies with the method; can be very fine or less even |
| Cost per kilo | Higher: more mills, more time, more upkeep | Lower |
| Typical use | Drinking matcha | Wide range, including processing and culinary use |
The comparison is general. A well-run modern mill can produce a good powder, and a stone mill run badly will not. The point for a buyer is that stone milling is a deliberate, slower choice that tends to favour texture.
Why heat matters
Heat is generally bad for matcha's colour and freshness. A peer-reviewed storage study found that colour and quality declined faster at higher temperatures over time. That study looked at storage after milling, not milling itself, but it shows why producers try to keep the powder cool at every stage. Slow stone milling generates little heat, which is one reason it remains the traditional choice for drinking matcha.
What milling means in your drinks
Texture
A fine, even powder disperses more easily, whisks smoother and leaves less sediment. An uneven powder with coarser particles can taste powdery or chalky, and leaves a fine sludge at the bottom of the cup. If you are dealing with that problem now, the guide to powdery or chalky matcha covers causes beyond milling, such as dose, water and technique.
Mouthfeel in usucha
In matcha whisked with water, there is nothing to hide texture. Smoothness and a soft foam are part of what a guest pays for.
Lattes
Milk is more forgiving, but grit still shows up, especially in iced drinks where the powder settles faster. A fine powder also forms a paste more quickly, which helps at peak times.
How to check milling yourself
You cannot measure particle size behind a bar, but you can run a simple comparison with samples:
- Rub test. Put a pinch between thumb and finger. It should feel silky, not sandy.
- Sieve test. Sieve 2 g through a fine tea sieve. Note how easily it passes and what remains.
- Settle test. Whisk 2 g into 60 ml of water, pour into a clear glass and leave it for five minutes. Compare how much sediment forms at the bottom.
- Taste test. Sip the last third of the glass. Note any grittiness.
Do the same test with each powder, same dose and same water, and write down what you see.
Why stone-milled matcha costs more
Stone mills are slow, so producing a given quantity takes many mills, many hours and regular maintenance of the stones. That cost goes into the price per kilo. The guide to wholesale price differences shows how milling fits alongside harvest, leaf selection and freight, and how to convert price per kilo into cost per serving.
What Yumi states
Both 1 kg products are stone-milled matcha from Uji (Kyoto), Japan, first harvest. Ceremonial Barista Matcha is made for milk drinks, and Ceremonial Matcha is made for pure preparation with water, where texture is most exposed.
Next step
Order the 10 g samples and run the four-step check above against your current powder. If the texture and flavour work in your drinks, move on to the 1 kg bag that fits your menu.