Matcha production is a linked sequence in which cultivation, rapid stabilization, cleaning, milling, and protective packaging all shape the final powder. The process does not begin at the grinder: farmers first alter leaf growth through shading, then processors work quickly to preserve the picked material before it becomes tencha and, finally, matcha.

Shading changes the leaf before harvest

The packet describes tea plants being covered with tana structures for 20–30 days before harvest, blocking 90–95% of sunlight. Under those conditions, chlorophyll production rises and the balance of leaf constituents changes. The covered fields are also reported to run 2–3°C cooler, slowing growth. Together, these effects support the green color and amino-acid-rich, umami-oriented character sought in matcha.

This stage distinguishes matcha-bound leaf from ordinary unshaded green-tea material. Shading must happen while the leaf is still growing; it cannot be recreated later by grinding or packaging. It is therefore a cultivation decision with consequences for every later production stage.

From picking to stable tencha

For selective harvesting, the packet identifies the terminal bud and top two leaves as the target. Hand picking can avoid bruising and exclude older growth, while mechanical harvesting is much faster but less selective. The intended grade and production scale help determine which method is practical.

Speed after picking matters because fresh leaves remain enzymatically active. The packet gives a 3–4 hour window for delivery to processing and describes steaming at 120°C for 20 seconds to stop that activity. Too little steaming can leave oxidation underway; too much can flatten the leaf’s character. Later processing cannot fully reverse damage that occurred while harvested leaves waited.

Unlike sencha, the steamed leaves are dried flat rather than rolled. The packet describes air drying at 180°C, followed by air separation that removes stems and veins. It reports that careful cleaning can remove 60–70% of the original leaf weight, leaving the soft leaf tissue called tencha. Tencha is not yet matcha: it is the cleaned, dried material prepared for grinding.

Slow milling turns tencha into matcha

Granite stone mills rotate slowly to limit heat while reducing tencha to particles reported at 5–10 microns. The packet gives a typical rate of 60 revolutions per minute and only 30–40 grams of powder per hour, with milling temperature kept below 25°C. The purpose of this low throughput is consistency without the heat associated with faster grinding.

Consider a producer who needs 300 grams of stone-milled matcha for a small release. At the stated output, one mill would require roughly 7.5–10 hours of grinding, before allowing for setup or cleaning. That simple example explains why milling capacity can constrain production even when plenty of tencha is available. An industrial ceramic grinder may produce far more per hour, but the packet warns that its higher heat can introduce burnt notes and damage heat-sensitive qualities.

Quality control and packaging

Before release, trained sensory panels assess color vibrancy, aroma complexity, and taste balance. The packet also describes laboratory checks for L-theanine, catechins, caffeine, and particle-size distribution. These measurements address different questions: sensory review judges how the matcha presents in the cup, while laboratory analysis checks composition and milling consistency.

Finished powder is then placed in nitrogen-flushed containers. Replacing oxygen slows oxidation, helping protect green color and delicate flavor during storage. Packaging is thus part of production quality, not a cosmetic final step.

Common process confusions

Tencha and matcha are related but not interchangeable: tencha is the de-stemmed, de-veined leaf material; matcha is the fine powder made by milling it. Shading is cultivation, steaming is stabilization, and grinding is particle reduction. A producer can perform one stage well and still lose quality elsewhere, so claims such as “stone-ground” describe only part of the chain. Cultivar, first-flush timing, shading, harvest selection, tencha cleaning, milling, testing, and oxygen-conscious packaging belong together when evaluating how a matcha was made.

Emilie Schol, author of "Production Process of Matcha".

By Emilie Schol

Emilie Schol founded Best Matcha after a biotechnology career, bringing a methodical, transparent and enthusiast-led approach to matcha discovery.
Last reviewed on August 2, 2026
First posted on August 25, 2025

Frequently asked questions

Here are some frequently asked questions and answers.

Why do matcha farmers shade tea plants before harvest?

Shading triggers a biological response that transforms ordinary tea leaves into matcha. When farmers cover plants with tana structures 20-30 days before harvest, blocking 90-95% of sunlight, the plants panic and boost chlorophyll production by 60%. L-theanine levels surge 40% higher compared to sun-exposed leaves. The covered fields also run 2-3°C cooler, which slows growth and concentrates amino acids—this is what creates matcha's sweet, umami-rich flavor profile that sets it apart from regular green tea.

How is matcha harvested and why does timing matter?

Only the top two leaves and terminal bud meet matcha standards, and they're hand-picked to avoid bruising that triggers oxidation. Here's the thing: picked leaves must reach processing facilities within 3-4 hours. Any delay allows enzymatic breakdown that creates off-flavors you can't remove later. Mechanical harvesting works 50 times faster but damages leaves and includes older growth, which is why it's reserved for lower grades. First flush harvests in April-May produce the sweetest matcha due to slower spring growth.

What's the difference between tencha and matcha?

Tencha is the leaf material that becomes matcha powder. After steaming, leaves are air-dried flat at 180°C instead of being rolled like sencha. Then air jets strip away stems and veins, leaving only soft leaf tissue. Quality operations remove 60-70% of the original leaf weight during this cleaning process. Inferior producers skip thorough de-stemming, which creates gritty matcha. So tencha is essentially the purified, pre-ground form—matcha is what you get after grinding tencha into fine powder.

Why are stone mills still used to grind matcha?

Granite grinding stones haven't changed since the 13th century for good reason. Each 400-pound stone set costs $20,000-30,000 and rotates at just 60 RPM, grinding only 30-40 grams hourly. That slow speed prevents heat buildup. Industrial ceramic grinders produce 5 kilograms hourly but generate heat exceeding 50°C, which destroys heat-sensitive compounds and creates burnt notes. The particle size must achieve 5-10 microns for proper suspension—stone mills deliver this consistency while keeping temperatures below 25°C.

How does the steaming process affect matcha quality?

Steam treatment happens at precisely 120°C for 20 seconds. It's a delicate balance. Shorter steaming preserves freshness but allows oxidation to continue, while longer steaming prevents oxidation but creates flat, spinach-like flavors the Japanese call 'naval-steamed.' This steaming stops enzymatic activity immediately, locking in the bright green color and fresh flavor. That's why leaves must reach processing facilities within 3-4 hours of picking—proper steaming can't fix damage from delayed processing.

What quality checks happen before matcha is packaged?

Every batch undergoes sensory evaluation by trained panels checking color vibrancy, aroma complexity, and taste balance. Laboratory testing confirms L-theanine content (ceremonial grade typically contains 20-40mg per serving), catechin levels, caffeine concentration, and particle size distribution. Packaging happens immediately in nitrogen-flushed containers to prevent oxidation. Replacing oxygen with nitrogen gas slows degradation of catechins and other antioxidants, preserving the vibrant green color and delicate flavor compounds throughout shelf life.

Sources

Sources and references

References supporting this page are listed below. Source access dates and supported claims are recorded in the evidence notes where available.
Updated on August 2, 2026
Portrait of Emilie Schol, Founder of Best Matcha

Emilie Schol

Founder of Best Matcha