Green Tea Catechins: How Much EGCG Is Actually in Your Cup

A standard 200 ml cup of brewed green tea contains roughly 50 to 100 mg of EGCG, the most abundant of its four main catechins. The exact figure depends far more on how you brew than on which tea you buy: steeping at 85 C for three minutes extracted a maximum of 50.69 mg per 100 ml in one controlled study, while a 20 C cold brew yielded under a tenth of that. Brew hot, brew short, and do not expect a second infusion to repeat the first.

What the four catechins are

Green tea catechins are a group of four flavan-3-ols: EGCG (epigallocatechin gallate), EGC (epigallocatechin), ECG (epicatechin gallate) and EC (epicatechin). Together they make up roughly 30 percent of the dissolved solids in a green tea infusion, compared with about 9 percent in a black tea, because oxidation converts most of them into larger theaflavins and thearubigins.

EGCG is the one that gets studied. It accounts for 25 to 50 percent of the dry weight of green tea leaf and between 50 and 80 percent of the total catechin fraction. The two gallated forms, EGCG and ECG, are the bitter ones and the ones most affected by heat; the non-gallated EGC and EC are lighter and more stable.

That ratio is why a green tea tastes the way it does. The gallate group on EGCG binds to the bitterness receptors on the tongue, which is why a strong green tea can taste bitter even with almost no astringency. It is also why over-steeping goes wrong so fast: the gallated catechins keep coming out after the pleasant compounds have finished.

Temperature: the 60 C surprise

Conventional advice says brew green tea cool to protect the catechins. The measurements are more interesting than that. A 2018 HPLC study across five temperatures found EGCG concentration peaking at 60 C, not at 80 C, and not at 100 C: 57.36 micrograms per millilitre at 60 C, falling to 36.13 at 80 C and rising again slightly to 44.85 at 100 C.

That dip at 80 C is not a measurement error. EGCG does two things when heated: it degrades, and it epimerises into GCG, a closely related compound. Between 60 and 80 C the epimerisation rate climbs faster than the extraction rate, so the EGCG number falls even though total catechin extraction is rising. At 100 C, extraction from the leaf outpaces the loss, and the number recovers.

None of this means you should brew at 60 C. A 60 C infusion extracts less of everything, including the amino acids that make the tea taste good, and the cup is thin. The practical reading is that EGCG is more robust than the folklore suggests: 80 to 85 C is a reasonable compromise between catechin yield and drinkability, and it is what most of the sensory literature recommends.

Time: three minutes, then decline

Steep time has an equally specific shape. A Turkish study brewing at 75, 85 and 95 C for times from one to forty-five minutes found EGCG content peaking at 85 C for three minutes, at 50.69 mg per 100 ml, then declining as steeping continued. The epistructured catechins, which include EGCG, rose sharply for the first three to five minutes and then fell.

The decline is real, not a plateau. Prolonged heat degrades the gallated catechins faster than fresh ones dissolve, so a ten-minute steep can contain less EGCG than a three-minute one. The same study found sensory scores collapsed for 30 and 45 minute brews at 85 and 95 C, because the bitter and dark compounds dominated.

So the practical window is narrow and well defined: 80 to 85 C, two to three minutes, one and a half to two grams of leaf per 100 ml. That is also, conveniently, how the tea tastes best. The chemistry and the palate agree here, which is not always the case.

Why matcha is a different order of magnitude

Brewed tea is an infusion: water passes through the leaf and carries away what dissolves. Matcha is the whole leaf, ground to a powder and suspended in the water, so you swallow everything. That is why a single teaspoon of matcha delivers roughly ten times the EGCG of an equivalent volume of brewed green tea.

It also means matcha delivers ten times the caffeine per serving, roughly 70 mg per 240 ml against 28 mg for brewed green tea, and ten times the fluoride. A 2026 survey of commercially available teas found fluoride ranging from 0.5 to 6.1 mg per litre, with matcha at the top of that range.

The catechin comparison is worth keeping in perspective. Ten cups of brewed green tea and one bowl of matcha are not the same thing nutritionally, but they are not wildly different either in total catechin terms. What differs is the delivery: a concentrated bolus from powder against a slow, dilute infusion from leaf.

What a second infusion actually contains

The first infusion takes the majority of the catechins. A second steep of the same leaf typically yields 30 to 40 percent of the first, and a third yields less than 15 percent. The decline is steeper for the gallated catechins, which are more soluble early and more prone to degradation later.

That is the chemistry behind the standard advice to drink green tea fresh and not to stretch the leaf. Two infusions is a reasonable limit for a fine green tea. Beyond that you are extracting color and bitterness with very little of the EGCG you were after.

Storage and the slow loss

Catechins degrade in storage, and they degrade faster in heat, light and moisture. A green tea held at room temperature in an open tin can lose a meaningful share of its EGCG within six months. Sealed, cold and dark, the loss is much slower but still real.

This is one of the few places where the health angle and the taste angle point the same way. A stale green tea tastes flat precisely because the volatile aroma compounds have gone, and the catechin loss tracks it. Fresh tea is both better drinking and a better source of the compounds people are chasing.

• Buy green tea in quantities you will finish within a year.
• Store sealed, dark and cold; let the tin reach room temperature before opening.
• Do not judge by color alone. A dull leaf can still be drinkable, but it has lost catechin.
• Avoid re-buying the same old stock at a discount; age is the one defect you cannot brew around.
• If you want a concentrated dose, matcha is the efficient route, with the caffeine that implies.

Comparing tea types

Green tea carries the most catechins of the six categories because nothing has oxidized them. White tea is close behind, since it is barely processed. Oolong has roughly half, black tea about a third, and dark tea the least of all, because fermentation converts the catechins into larger compounds.

That ranking is about catechin content, not about which tea is better for you. A dark tea has compounds a green tea does not, and the evidence for any of them producing a clinical outcome is thin. If your interest is specifically EGCG, green tea and matcha are the sensible choices, and the brewing method matters more than the price of the leaf.

Why leaf grade changes the number

Two green teas brewed identically can differ by a factor of two in EGCG. The variable is the leaf itself. A bud-heavy spring pick carries more soluble solids per gram than a coarse late-season leaf, and a shaded Japanese leaf carries more than a sun-grown one because shading pushes the plant toward amino acids and away from the defensive polyphenols.

Processing matters too. A pan-fired Chinese green and a steamed Japanese green retain catechins in similar quantities, but the steamed leaf keeps more chlorophyll and a different volatile profile, so the cup tastes different even when the numbers are close. The catechin content is roughly comparable; the experience is not.

What does not change the number much is price. An expensive Longjing and a modest everyday green from the same province can have similar catechin content, because catechin is a defensive compound the plant makes regardless of how carefully it is handled. You are paying for aroma, shape and labor, not for EGCG.

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