Black, green, white and oolong teas all come from the same plant, Camellia sinensis, processed differently. Black tea is fully oxidized and strongest in flavor; green tea is unoxidized and grassy; oolong is partly oxidized; white tea is minimally processed. All contain caffeine, generally less than coffee: an 8-ounce cup of black tea has roughly half the caffeine of brewed coffee. Herbal teas such as chamomile and rooibos are naturally caffeine-free.
All “true” teas come from one plant. Processing creates the differences in flavor and caffeine.
The main types
| Type | Processing | Flavor | Caffeine |
|---|---|---|---|
| Black | Fully oxidized | Malty, robust | Higher |
| Oolong | Partly oxidized | Floral to roasted | Medium |
| Green | Unoxidized, heated to stop oxidation | Grassy, vegetal | Lower to medium |
| White | Minimally processed | Delicate, sweet | Low to medium |
| Matcha | Powdered shade-grown green tea | Rich, umami | High (you consume the leaf) |
| Herbal | Not from the tea plant | Varies | None (most) |
Caffeine compared
As a rough guide per 8 oz (240 ml) cup:
| Drink | Approximate caffeine |
|---|---|
| Brewed coffee | About 95 mg |
| Black tea | About 40 to 50 mg |
| Green tea | About 25 to 30 mg |
| Herbal tea | 0 mg |
Actual amounts vary with leaf type, quantity and steep time.
Brewing basics
| Tea | Water temperature | Steep time |
|---|---|---|
| Black | Just off the boil | 3 to 5 min |
| Oolong | About 85 to 95 °C | 3 to 5 min |
| Green | About 75 to 80 °C | 2 to 3 min |
| White | About 75 to 85 °C | 3 to 5 min |
| Herbal | Boiling | 5 to 7 min |
Too-hot water and long steeps make green and white teas bitter.
Loose leaf vs bags
Loose leaf usually has larger, whole leaves and more flavor, and can often be re-steeped. Tea bags are convenient; pyramid bags give leaves more room to expand.
Common questions
Which tea has the most caffeine?
Black tea and matcha generally have the most caffeine among teas, but amounts vary widely by leaf, amount used and steep time.
Does green tea have caffeine?
Yes, usually less than black tea. Steeping it for a shorter time with cooler water also reduces bitterness.
Which teas are caffeine-free?
Herbal teas (tisanes) such as chamomile, peppermint, rooibos and hibiscus are naturally caffeine-free because they don't come from the tea plant.