Catechins
The antioxidant compounds responsible for tea's health-related effects.
Catechins are a class of polyphenol antioxidants concentrated in tea leaves. Matcha contains four main catechins: EGCG (the most studied), EGC, ECG, and EC. Total catechin content in matcha runs roughly 50 to 140 mg per gram, with EGCG making up about half. Because matcha is consumed as the whole ground leaf rather than steeped, you ingest more catechins per cup than from any infusion-only green tea — typically 2× to 3× more, not the 137× sometimes claimed in marketing.
In practice
- The family of polyphenols responsible for most of green tea's astringency, of which EGCG is the largest member.
- Matcha contains them at high concentration and, unusually, you swallow all of them rather than straining the leaf away.
- Sunlight drives production up, so unshaded sencha is more catechin-heavy and briskly astringent than shaded matcha or gyokuro.
- They extract faster in hotter water, which is the practical reason cooler brewing tastes sweeter.
The common mistake
Confusing astringency with bitterness. Catechins are astringent — mouth-drying, like a young red wine. Bitterness is a separate taste and, in matcha, usually a sign of water that was too hot or leaf that was too old.
