Matcha Grading Standards — No Universal System
Matcha grading is not regulated by any international standard. Japanese industry benchmarks include L-theanine ≥35mg/g for ceremonial, CIELAB L* ≤52 for color, and particle size ≤10μm — but these are voluntary and not enforced outside certification schemes.
| Measure | Value | Unit | Notes |
|---|---|---|---|
| L-theanine threshold: ceremonial grade | ≥35 | mg/g | Industry benchmark; not legally mandated |
| Particle size: ceremonial grade | ≤10 | μm | 5–10μm target; measured by laser diffraction |
| CIELAB L* value: ceremonial | ≤52 | L* | Lower = darker green = higher chlorophyll |
| CIELAB a* value: high-quality matcha | −11 to −9 | a* | Negative a* = green; more negative = greener |
| Moisture: all grades | ≤5 | % | Higher moisture causes clumping and accelerates degradation |
| Countries with regulated matcha standards | 0 | No country has legally binding matcha grade standards as of 2026 |
The absence of universal grading standards is the single largest source of consumer confusion in the matcha market. Unlike coffee (which has established SCA grading), wine (AOC/GI protection), or olive oil (EU grades), matcha grades are entirely self-declared by producers and retailers.
What Objective Metrics Exist
The Japanese tea industry and researchers have identified measurable parameters that correlate with quality:
| Parameter | Ceremonial | Premium Culinary | Standard Culinary |
|---|---|---|---|
| L-theanine | ≥35 mg/g | 20–35 mg/g | 10–20 mg/g |
| Particle size | ≤10 μm | 10–15 μm | 15–25 μm |
| CIELAB L* | ≤52 | 52–58 | 58–65 |
| CIELAB a* | −11 to −9 | −9 to −7 | −7 to −5 |
| Stem content | <5% | 5–15% | 15–30% |
These are industry benchmarks, not legal standards. A producer can label matcha as “ceremonial” with L-theanine of 20mg/g and no enforcement action will follow.
ISO and Codex Standards
ISO 11287:2011 covers green tea definitions and basic physical/chemical requirements, but does not address matcha specifically. Codex Alimentarius Standard CXS 69-1981 covers tea (including green tea) but predates the matcha market’s globalization and lacks matcha-specific parameters.
How to Grade Without Standards
In the absence of regulated standards, buyers can:
- Request lab analysis certificates (L-theanine content, pesticide residue tests)
- Use physical observation (color, aroma, texture — see color-indicators page)
- Trust geographic indicators (Uji, Nishio, Yame origin matcha from established producers)
- Use sensory tests (straight water preparation; ceremonial grade should be sweet and umami-forward)
The growing premium matcha market is beginning to self-regulate, with some producers publishing comprehensive QA data. This transparency is the best current substitute for formal standardization.