Green tea vs black tea: what's actually different?

Green tea and black tea come from the same plant but are processed differently. Compare caffeine, flavor, antioxidants, and brewing technique for both.

By PGP Iyer · April 30, 2026 · 2 min read

Every cup of green tea and black tea begins with the same plant: Camellia sinensis. The difference is what happens after the leaves are picked.

Processing: oxidation is the dividing line

Black tea is fully oxidized — leaves are bruised, exposed to oxygen, and allowed to turn dark before drying. The reaction develops the malty, robust flavors and the deeper amber color in your cup.

Green tea skips oxidation entirely. Leaves are heated soon after picking (steamed in Japan, pan-fired in China) to deactivate the enzymes that would otherwise turn them brown. The result: a fresher, vegetal cup that retains more of the leaf's original chlorophyll and catechins.

Caffeine

• Green tea: ~25–45 mg per 8oz cup
• Black tea: ~40–70 mg per 8oz cup
• Coffee (for reference): ~95 mg per 8oz cup

Flavor profile

Green tea ranges from grassy and oceanic (Japanese sencha) to nutty and toasty (Chinese longjing). Black tea ranges from malty (Assam) to floral (Darjeeling) to brisk and citrusy (Ceylon).

Health benefits

Both teas contain polyphenols. Green tea is highest in EGCG, a catechin studied for cardiovascular and metabolic effects. Black tea's oxidation converts catechins into theaflavins and thearubigins — different compounds with their own studied benefits, particularly for cholesterol.

How to brew each

Green tea

• Water: 70–80°C (160–176°F)
• Time: 1–2 minutes
• Why lower temp: prevents the catechins from turning bitter

Black tea

• Water: 95–100°C (203–212°F)
• Time: 3–5 minutes
• Why hotter: needed to fully extract the oxidized compounds