The bowl glows vivid green — a color that almost hums with intensity — and the flavor that follows is grassy-sweet with a clean savory depth. Everything about Matcha traces back to a specific manufacturing path that begins months before harvest and ends with stone grinding at a rate of roughly 40–60 grams per hour per mill.
Matcha starts as Tencha: shade-grown leaf, steam-fixed, dried without rolling, then de-veined and de-stemmed before being stone-milled into the fine powder we know. That sentence covers the essentials. The details explain why Matcha is unlike any other tea.
What is Tencha — the raw material of Matcha
Shade cultivation — 20 or more days under canopy
Three to four weeks before the first-flush harvest, the tea fields that will produce Tencha are covered. Traditionally this meant reed screens (*yoshizu*); modern operations often use synthetic shade cloth that can be deployed and adjusted more precisely. The goal is to block 70–90% of direct sunlight. What happens inside that shaded environment is the foundation of Matcha's character.
Deprived of full sunlight, the tea plant cannot photosynthesize efficiently. To compensate, it ramps up chlorophyll production — which is why shade-grown leaves are an unusually intense, almost bluish green. Simultaneously, the plant produces more L-theanine (the amino acid responsible for Matcha's umami sweetness) but converts less of it to catechins (the compounds responsible for astringency). The result is a leaf chemistry shifted toward sweetness, umami, and vivid color — and away from the bitterness that full-sun leaves carry.
More on the mechanics of this process is in our covered cultivation guide.
How shading changes the leaf chemistry
The theanine-to-catechin ratio in shaded leaves is dramatically different from unshaded ones. A first-flush Sencha grown in full sun might have a catechin content of 12–15% by dry weight. A Tencha leaf from the same cultivar, shaded for 25 days, might drop to 7–10% catechins while theanine roughly doubles. Chlorophyll concentration increases by 30–40%, which accounts for the vivid color of the brewed bowl and the powder itself.
From harvest to Tencha — the processing steps
Tencha is first-flush only. The timing — typically late April to early May in Uji — matters because the young leaves carry the highest theanine concentrations. Harvesting is increasingly machine-assisted, though premium producers still use hand-picking for the finest grades.
| Step | What happens | Key difference from Sencha |
|---|---|---|
| Picking | First-flush leaves harvested (one bud + 2–3 leaves) | Same as Sencha |
| Steaming (mushi) | Short steam (5–15 seconds) to deactivate oxidative enzymes | Shorter steam than most Sencha |
| Cooling/blowing | Leaves are blown rapidly to cool and separate; aracha forms | No rolling at any stage |
| Tencha oven drying (tencha-ro) | Dried in a special Tencha oven with layered conveyor belts at 150°C+ | Flat, unrolled drying — unique to Tencha |
| De-veining / sorting | Stems and leaf veins removed; leaf pieces sorted by quality | Essential step — veins and stems would create gritty powder |
| Blending | Different Tencha lots blended for target color, flavor, and consistency | Same in principle as other tea finishing |
| Stone-milling | Tencha ground between granite millstones into fine powder | Unique to Matcha — no other Japanese tea is ground |
The absence of rolling is the defining difference between Tencha and every other Japanese green tea. Rolling — the kneading and shaping that gives Sencha its needle-like form — breaks cell walls, concentrates flavor, and changes the texture of the finished tea. Tencha skips this entirely. The leaf is dried flat, which preserves the delicate cell structure needed for clean, smooth milling later.
The Tencha oven — a unique piece of infrastructure
The drying oven for Tencha is unlike any other tea-drying machine. A typical unit is several meters tall, with three conveyor belts stacked vertically. Leaves enter at the bottom belt on the highest heat (over 150°C), are blown upward to the top belt for rapid initial drying, then travel down through progressively lower-heat zones. The entire drying run takes about 20–30 minutes. The result is a dry, fragile, flat leaf — the aracha Tencha — that still carries all the veins and stems that need to be removed.
Milling — the stone grind that defines Matcha
Granite millstones and their speed
Once the Tencha has been de-veined, sorted, and blended, it is stored under carefully controlled temperature and humidity until just before milling. Matcha oxidizes quickly once milled — the high surface area of fine powder accelerates contact with air and moisture. Milling close to production or shipment is standard practice for quality-conscious producers.
The millstone is granite, typically about 30cm in diameter. The upper stone rotates above the fixed lower stone; the Tencha feeds through a small hole in the center, is gradually ground between the faces as it moves outward, and exits as fine powder at the edges. Speed matters: too fast and the friction generates heat that degrades the flavor compounds. The standard is 30–40 rotations per minute, producing 40–60 grams of Matcha per hour per mill. A single stone mill operating for eight hours produces roughly 400 grams of powder. It is slow by any industrial standard — and that is the point.
Why particle size matters for flavor and color
Stone-milled Matcha has a particle size of around 5–10 microns. At that size, the powder is fine enough to suspend in water rather than sink — it disperses when whisked, creating the characteristic frothy bowl. Coarser machine-milled powder (sometimes 20–30 microns) requires more effort to whisk smooth, settles faster, and often tastes gritty rather than silky. The color is also different: finer particle size means more light scattering, which gives stone-milled Matcha its vivid, almost luminous green. Machine-milled tends toward a duller, more olive tone.
Machine milling vs. stone milling
Ball mills and cryogenic grinding systems can produce fine particle sizes at volume, and some are genuinely impressive. The difference is heat. Stone milling keeps the Tencha cool throughout. High-speed mechanical milling generates heat that volatilizes aroma compounds and can alter catechin structure. Whether this is perceptible in the cup is a matter of debate — but among Matcha producers and serious practitioners, stone milling is the benchmark.
Production regions — terroir and cultivar selection
Matcha is produced across several Japanese prefectures, each with distinct climate and soil characteristics that shape the finished tea. Uji in Kyoto Prefecture, Nishio in Aichi Prefecture, and Shizuoka Prefecture are the historically dominant regions, while Kagoshima Prefecture has emerged as a major producer over the past decade — now among the highest in Tencha output by volume. Each region has a distinct terroir profile.
Uji benefits from the confluence of three rivers — the Uji, Kizu, and Katsura — which create morning fog and high ambient humidity. The fog acts as natural shading in early morning, extending the slow growth that deepens theanine accumulation. The region has been producing shaded tea for over 600 years, and the cultivars selected for Uji's conditions — Samidori, Okumidori, Asahi — are distinct varieties adapted to that microclimate.
Nishio, in inland Aichi, has slightly warmer temperatures and well-drained soils that produce a more robust Tencha. The flavor profile tends toward a more assertive sweetness, with less of the delicate floral quality associated with Uji. Nishio produces a large volume and is particularly strong in ceremonial-grade blends for export.
Shizuoka's cooler mountain areas — particularly Kakegawa and the upland regions — have experimented with Tencha production, with results that often emphasize a grassier, more herbaceous character. Regional variations in cultivar and soil give Shizuoka Matcha a distinctive personality, even if the name recognition is lower than Uji or Nishio.
Cultivar selection interacts with terroir in important ways. Samidori, long associated with Uji, produces a vivid green color and a complex sweetness. Okumidori is valued for deeper color and stable flavor. Asahi — one of the oldest cultivars in Uji — has a more delicate, nuanced flavor that commands a premium.
Tencha vs. Matcha — clearing up the confusion
Tencha and Matcha are not two different teas. They are the same leaf at different stages of processing. Tencha is the finished, de-veined dried leaf. Matcha is what Tencha becomes when it passes through the stone mill. You cannot brew Tencha the way you brew Sencha — it is too fragile and its flavor compounds are not designed for steeping whole. Its entire value is realized through milling.
If you ever see "Tencha tea" sold as a brewed loose-leaf, it is unusual but not impossible — some producers offer it for curiosity. The flavor is flat and vegetal compared to the bowl of Matcha it would become. The milling is not decorative. It is the transformation.
For the distinction between Matcha grades and what to look for when choosing, our ceremonial grade Matcha guide covers that ground directly. For what to do with the powder once you have it, the Matcha preparation guide walks through both usucha and koicha styles. Related context on the unoxidized tea manufacturing process is in our overview of Japanese green tea processing, and the full context of where Matcha sits in the green tea family is in our Matcha vs. green tea comparison.
The patience required at every stage — the weeks of shading, the hours of stone milling, the careful temperature control through drying and storage — is what makes Matcha irreplaceable. Every cup is the product of that accumulated care.
If you want to taste the difference that stone milling makes, explore our Matcha and tea leaves.
Because Tencha is shade-grown before processing, the final Matcha powder has notably high caffeine. For a full breakdown, see our guide to Matcha caffeine content.