Chlorophyll in Matcha — Shade-Growing Effects
Matcha tea plants covered for 20–30 days accumulate 3–5× more chlorophyll than sun-grown green tea. This elevated chlorophyll content produces the vivid green color and contributes umami flavor through the inhibition of normal photosynthetic degradation.
| Measure | Value | Unit | Notes |
|---|---|---|---|
| Chlorophyll a in shade-grown tea leaves | ~900–1200 | mg/100g dry weight | Vs. ~200–400 mg/100g in sun-grown green tea |
| Chlorophyll b in shade-grown tea leaves | ~300–500 | mg/100g dry weight | Ratio of a:b ~3:1; both increase under shading |
| Chlorophyll increase from shading | 3–5× | Compared to the same cultivar grown in full sun | |
| Color: L* value (CIELAB) of high-quality matcha | ~47–52 | L* | Darker green than steeped tea liquor; higher L* = paler/lower quality |
| Chlorophyll degradation (pheophytin) in old matcha | significant | Pheophytin has olive-yellow hue; sign of age/oxidation |
Chlorophyll is the photosynthetic pigment that makes plants green. In matcha, its elevated concentration is not an accident of nature but a deliberate engineering outcome of the shade-growing process.
Why Shade-Growing Increases Chlorophyll
Under reduced light conditions, tea plants upregulate chlorophyll synthesis as a compensatory response. By producing more chlorophyll, the plant maximizes its ability to capture what little light is available. This response is analogous to how shade-tolerant plants in forest undergrowth develop deeper green leaves than sun-exposed canopy species.
The relationship is roughly linear: greater shade duration and percentage light reduction produces more chlorophyll accumulation, up to a physiological ceiling.
Chlorophyll as Quality Indicator
High-quality matcha is distinguished by its vivid green color — described in Japanese tasting terminology as “midori” (鮮やか緑). The color intensity correlates directly with chlorophyll content:
- High quality: Deep, bright green with slight blue-green undertone
- Medium quality: Grassy green, slightly lighter
- Low quality or aged: Yellow-green, olive, or dull — indicates either low chlorophyll from sun-growing or pheophytin formation from degradation
When matcha oxidizes (from heat, light, or moisture), chlorophyll loses its central magnesium atom and becomes pheophytin, which is olive-yellow. This is why old or poorly stored matcha looks yellow-green rather than bright green.
Chlorophyll and Flavor
Chlorophyll itself has a mildly grassy, vegetal taste. Its elevated concentration in shade-grown matcha contributes to the characteristic “matcha” flavor profile — distinct from sencha (unshaded green tea), which tastes more astringent and grassy with less umami depth.
Health Claims Around Chlorophyll
Chlorophyll is sometimes marketed for “detoxification” properties. The evidence base for chlorophyll as a detox agent in humans is weak at clinically relevant doses. The chlorophyll in matcha (approximately 1–3mg per serving) is unlikely to produce significant physiological effects beyond its antioxidant contribution.