Updated July 2026
Green tea and black tea are made from the leaf of the same plant, Camellia sinensis. What separates them is a single step: oxidation. To make green tea, the fresh leaf is heated soon after picking, a step called kill-green, which stops the leaf's own enzymes and keeps it green and vegetal. To make black tea, known in China as red tea, the leaf is left to oxidise fully, so its compounds change and darken, giving the deeper, brisker cup. It is not a different plant and, despite the common word, black tea is not truly fermented: it is oxidised by the leaf's own enzymes. One leaf, two decisions about when to stop.
| Green tea | Black tea (red tea) | |
|---|---|---|
| Plant | Camellia sinensis | Camellia sinensis |
| Key step | Fixed early (kill-green), little oxidation | Fully oxidised |
| In the cup | Fresh, green, lighter | Deep, brisk, darker |
| Caffeine | Present, often less | Present, often more |
Oxidation is not fermentation
The trade often calls black tea "fermented," but that is loose language. Oxidation is the leaf's own enzymes acting on its own compounds once the leaf is bruised, not microbes at work. True microbial fermentation belongs to dark teas such as ripe puer, which is a different process again. For green and black tea, the honest word is oxidised.
The same leaf, a different hour
Between green and black sit the partly oxidised teas, the oolongs, halted somewhere in the middle. This is the quiet genius of tea: one plant, and a whole spectrum of character drawn out by how and when the maker stops the leaf. In Yangsheng Cha Dao, all of it is tea, because all of it is Camellia sinensis.
Frequently asked questions
Are green tea and black tea from different plants?
No. Both come from Camellia sinensis. The difference is oxidation: green tea is heated early to stay green, black tea is fully oxidised.
Is black tea fermented?
Not truly. Black tea is oxidised by the leaf's own enzymes, not by microbes. Only dark teas such as ripe puer are genuinely fermented by microbial action.
Does black tea have more caffeine than green tea?
Often, though it varies with the leaf and how it is brewed. Both contain caffeine because both are Camellia sinensis.