Green Tea vs Black Tea: What's the Difference?
Green tea and black tea come from exactly the same plant: Camellia sinensis. The difference between them is entirely in how the leaves are processed after harvesting. That single variable (oxidation) creates two teas that taste completely different, have different caffeine levels, different antioxidant profiles, and work best in different situations.
The Processing Difference
After tea leaves are picked, enzymes in the leaf begin a process called oxidation (sometimes called fermentation, though that term is not technically accurate). Left alone, the leaf turns from green to brown, similar to a cut apple browning on the counter.
To make green tea, producers stop oxidation quickly by applying heat (steaming in Japan, pan-firing in China). The leaf stays green, and the flavor stays fresh, grassy, and light.
To make black tea, producers allow the leaf to oxidize fully. The leaf turns dark brown and the flavor becomes richer, bolder, and more complex. The oxidation process produces the robust, malty, or fruity notes characteristic of black teas like Assam and Darjeeling.
Oolong tea sits between the two: partially oxidized, with flavor characteristics that fall somewhere on the spectrum from green to black depending on the specific processing.
Caffeine Content
| Tea Type | Caffeine per 8oz |
|---|---|
| Black Tea | 40 to 70 mg |
| Green Tea | 25 to 45 mg |
| White Tea | 15 to 30 mg |
| Oolong Tea | 30 to 50 mg |
Black tea generally has more caffeine than green tea, though the range overlaps considerably depending on the specific variety, how the leaf was processed, and how long you steep it. A 5-minute steep of a strong Assam will have noticeably more caffeine than a 2-minute steep of a delicate Darjeeling.
Both contain L-theanine, the amino acid that modulates caffeine's effect in the brain. Green tea typically has a higher L-theanine to caffeine ratio, which may contribute to the "calm alertness" quality many people associate with green tea compared to the more assertive energy of black tea.
Antioxidant Differences
Both teas contain significant antioxidants, but of different types. Green tea is high in catechins (particularly EGCG, epigallocatechin gallate), which are among the most studied plant polyphenols. The quick processing that prevents oxidation preserves these compounds at high levels.
Black tea contains fewer catechins (they are converted during oxidation) but is high in theaflavins and thearubigins, compounds that form during oxidation and have their own antioxidant and anti-inflammatory properties. Research on both sets of compounds is ongoing, and neither tea is definitively "better" in terms of antioxidant value for all purposes.
Flavor: What to Expect from Each
Green tea is grassy, vegetal, and sometimes slightly sweet (particularly Japanese varieties like sencha and gyokuro). Chinese green teas tend to have more toasted, nutty notes. The flavor is delicate and can turn bitter quickly if brewed at too high a temperature or for too long.
Black tea is bold, malty, sometimes fruity (Darjeeling, particularly second-flush), and can handle milk and sweeteners without losing its character. The bitterness from tannins is more noticeable than in green tea but can be controlled through brew time and temperature.
Our Hound of Zencha is a Japanese-style sencha that shows the clean, sweet side of green tea. Our Earl Greyhound is a premium bergamot black tea that demonstrates the aromatic, complex side of black tea at its best.
How to Brew Each Correctly
This is where most people go wrong with green tea specifically. Boiling water (212 F) is ideal for black tea but will make most green teas harsh and bitter. Green tea should be brewed at 160 to 175 F and steeped for only 2 to 3 minutes. If you bring water to a boil and then let it sit for 3 to 4 minutes, it cools to roughly the right range.
Black tea is more forgiving: steep at 200 to 212 F for 3 to 5 minutes. Adding milk reduces the tannin astringency and is standard for strong Assam blends and chai-style teas.
Which Should You Drink?
The honest answer is that it depends on what you want from the cup. If you want a strong, warming morning drink that holds up with milk: black tea. If you want a lighter, cleaner energy with a more delicate flavor for mid-morning or afternoon: green tea. If you want the maximum caffeine from tea without switching to coffee: a strong black tea or yerba mate.
Many regular tea drinkers keep both. A strong chai or Earl Grey in the morning, a sencha or green tea in the afternoon when you want less caffeine and a lighter cup.
Browse our full tea collection to compare green and black options side by side, or explore our herbal blends for caffeine-free alternatives.