Facts about Chlorophyll: Matcha's Vivid Green Has Nothing to Do With Why It Tastes Good

Here is where Japanese tea agriculture becomes genuinely fascinating.

Under normal growing conditions, sunlight drives photosynthesis, which is efficient and productive for the plant. But when a tea plant is deprived of sunlight, something interesting happens. It essentially goes into a kind of overdrive, producing more chlorophyll in an attempt to capture whatever light is available. The plant is working harder with less.

Research published in Frontiers in Plant Science has confirmed the molecular mechanism behind this: shading activates specific chlorophyll synthesis genes in the tea plant, leading to a measurable increase in chlorophyll content, larger chloroplasts, and darker, more intensely green leaves.² Chloroplasts are the tiny structures inside plant cells that contain chlorophyll and are where photosynthesis takes place. Think of them as the plant's solar panels. When the plant is deprived of light, it responds by building more and larger solar panels in an attempt to capture whatever is available, which is why shaded leaves end up so much darker and richer in chlorophyll than leaves grown in full sun.

For Japanese shade-grown teas, this process is carefully controlled. Matcha and gyokuro are produced using a traditional cultivation system that reduces sunlight reaching the plants by typically 85 percent or more, applied for 20 to 30 days before the spring harvest.³ The result is leaves with significantly higher chlorophyll content than those grown in full sun.

A peer-reviewed analysis of chlorophyll profiles across multiple Japanese green tea varieties found that matcha contains higher proportions of both chlorophyll a and chlorophyll b than other varieties, including gyokuro and sencha, specifically because the entire shaded leaf is consumed as a fine powder rather than steeped and discarded.⁴ When you drink matcha, you are consuming the full chlorophyll content of the leaf.

This is an aspect of chlorophyll that very few people outside the tea industry know about, and it is practically valuable.

Chlorophyll is not stable. It degrades over time when exposed to light, heat, oxygen, and acidity. As it breaks down, it converts into compounds called pheophytins and pheophorbides, which are brownish-green rather than bright green.⁵ This is the chemistry behind why old or poorly stored matcha turns from vivid green to a dull, yellowish-grey.

I'm sure that part hit an 'aha' moment for some of the Matcha loving readers.

A scientific study specifically investigating chlorophyll as a freshness indicator found that chlorophyll concentration in green tea begins declining measurably from the second month of storage, and that decline accelerates significantly from the sixth month onward.⁶ Packaging matters enormously: the study found that metal or opaque packaging preserves chlorophyll far better than glass or paper exposed to daylight.

This means the color of matcha is not just about appearance. It is a direct proxy for freshness and storage quality. Vivid, deeply saturated green indicates intact chlorophyll and a recently harvested, well-stored product. A dull, brownish-grey or yellow-toned matcha tells you that the chlorophyll has begun breaking down, and that the overall compound profile of the tea has degraded alongside it.

The ratio of intact chlorophyll to its degradation products has become a recognized tool in tea quality assessment. Research confirms that pheophytins and pheophorbides are considered markers of lower quality in green tea, precisely because their presence signals that the tea's chlorophyll integrity has been compromised.⁷

This is where the story takes a turn that surprises most people.

Chlorophyll is not the reason Japanese green tea tastes good. In fact, chlorophyll itself is associated with a grassy, slightly bitter, and vegetal flavor. It is the kind of taste you recognize in fresh spinach or kale, or in a very grassy sencha brewed too hot. Research on green tea flavor consistently identifies taste quality as being driven by amino acids, particularly L-theanine, which contributes umami and sweetness, and by the balance of catechins, sugars, and caffeine. Chlorophyll and its derivatives are listed among the color-determining compounds, not the taste-determining ones.⁸

The grassy notes that some people associate with green tea, and that can tip into bitterness when tea is brewed incorrectly, are partly attributable to chlorophyll. But the reason shade-grown teas like gyokuro and matcha taste sweet and umami-rich rather than grassy and bitter is not because of their high chlorophyll. It is because shading simultaneously suppresses catechin development and increases amino acid accumulation, particularly L-theanine. The chlorophyll is present in abundance during this process, but it is essentially riding along rather than driving the taste.⁹

The important takeaway is this: high chlorophyll content is a result of the same shading process that produces great-tasting tea, but chlorophyll and great taste are not the same thing. They are companions produced by the same conditions, not interchangeable indicators of each other. A tea can have high chlorophyll and taste grassy. A tea can have lower chlorophyll and taste exceptional. What shading does is create the conditions for both simultaneously.

This separation becomes very clear when you look at cultivar differences within Japanese green tea. Tea farmers have long understood that chlorophyll content and umami intensity do not move together in lockstep. Saemidori, for example, is a cultivar prized for its exceptionally rich umami and sweetness, yet its leaves are relatively light in green color compared to other shade-grown varieties. Okumidori, by contrast, produces leaves with a notably deep, saturated green color and high chlorophyll content, but it is not particularly renowned for umami depth. In practice, this distinction shapes how blenders work: Okumidori is frequently used as a blending component specifically to improve the visual appearance of matcha powder, lending it a more vivid green that signals quality to the eye of a consumer. The fact that this is a recognized practice in the industry is perhaps the clearest illustration of how chlorophyll and taste quality are related but distinct dimensions of a tea.

Before discussing what chlorophyll may do for the body, there is one essential piece of context that changes how you should think about this topic: chlorophyll is fat-soluble, not water-soluble. This means it does not dissolve into hot water during brewing. When you steep a conventional loose-leaf tea and discard the leaves, the chlorophyll stays almost entirely in the leaf and never enters your cup. Research confirms that approximately 60 to 70 percent of matcha's nutrients are insoluble compounds, chlorophylls included.¹⁰

The practical implication is straightforward: the health benefits of chlorophyll in green tea are relevant primarily in the context of matcha, where the entire leaf is consumed as a fine powder suspended in water. Drinking brewed sencha or gyokuro, however high quality, does not deliver meaningful amounts of chlorophyll to your body. Matcha is the exception, and this is one of the reasons it occupies a distinct place in both Japanese tea culture and nutritional research.

With matcha as the frame, here is what the peer-reviewed evidence on chlorophyll currently supports:

Antioxidant and anti-inflammatory activity. A comprehensive review published in PMC found that chlorophylls and their derivatives exhibit antioxidant, antimutagenic, and antigenotoxic properties, meaning they show some capacity to neutralize free radicals and reduce the kind of cellular damage associated with chronic disease and aging.¹¹

Detoxification support. Clinical trials have demonstrated that chlorophyllin can reduce the bioavailability of aflatoxins, which are potent carcinogens produced by certain molds, by up to 55 percent compared to placebo. Chlorophyll appears to physically bind to these toxins in the digestive tract, helping the body eliminate them before they are absorbed.¹²

Potential blood sugar benefits. More recent research has found that certain chlorophyll derivatives may slow carbohydrate digestion by inhibiting specific digestive enzymes, with potential implications for blood sugar management. Most findings are currently from animal or in vitro models, and human clinical trials are still needed.¹³

Anticancer research. Studies have found that removing chlorophylls from green tea and olive leaf extracts eliminated a significant portion of their cytotoxic activity against tumor cells, suggesting chlorophyll contributes to anticancer effects beyond the phenolic compounds alone. Most of this evidence comes from laboratory models rather than human clinical trials, and substantial further research is needed.¹⁴

Chlorophyll in Japanese green tea tells a layered story. It is the direct product of the shading practices that define matcha and gyokuro. Its presence and vibrancy is the most reliable visual indicator of freshness and quality available to the naked eye. Its grassy, slightly bitter flavor character is real but is balanced and largely overshadowed in high-quality shade-grown teas by the amino acids that shading simultaneously produces. And crucially, because chlorophyll is fat-soluble and does not dissolve into brewed tea, its health benefits are specifically relevant to matcha drinkers who consume the whole leaf.

The cultivar examples of Saemidori and Okumidori illustrate perfectly that color and quality are related but not the same. The industry practice of blending for color is itself the clearest evidence that what looks most like matcha and what tastes most like great matcha are two different things, produced by the same plant but shaped by different forces.

What the color of matcha is really telling you is not just that a compound is present. It is telling you about the entire story of how that tea was grown.

Tealife is a Singapore-based distributor of premium Japanese tea brands including Marukyu Koyamaen and Ippodo. The information in this article is for educational purposes and does not constitute medical advice.