Generally speaking oolong tea contains more caffeine than green tea, but how does it compare to coffee?
Oolong Tea Caffeine versus Green Tea
Oolong tea, like other tea types, it's made from the Camellia Sinenses tea plant. When compared to green tea, it's more oxidized and more water content has been removed during the production processes. Due to this intensive processing, the tea is more concentrated and contains more caffeine.
According to the statistics by USDA, 3.5oz (100ml) of brewed green tea contains 12mg caffeine, while 3.5oz (100ml) of oolong contains approximately 16mg. So generally speaking, green tea has 25% less caffeine relative to oolong tea.
Note that with artisan tea, resellers often recommend lower steeping temperatures for green tea relative to oolong. Therefore, less caffeine gets extracted from green tea in practice.
Oolong Tea Caffeine versus Coffee
It's however safe to assume that oolong tea contains less caffeine than a cup of coffee. According to the statistics from USDA, an 3.5oz (100ml) brewed cup of coffee contains about 42mg caffeine, while a cup of 3.5oz (100ml) brewed cup of oolong contains about 16mg of caffeine.
Green Tea Caffeine versus Coffee
A 3.5oz (100ml) of brewed green tea has significantly less caffeine (12mg) compared to the same amount of coffee (42mg).
So let summarize the info:
- 3.5oz (100ml) cup of coffee: 42mg of caffeine
- 3.5oz (100ml) cup of oolong: 16mg of caffeine
- 3.5oz (100ml) cuo of green tea: 12mg of caffeine
Kinds of Coffee, Ways of Brewing Tea
One should understand that the above figures are average values. For example, an Espresso is brewed much stronger than an Americano. Thus an Expresso coffee, will have higher concentrations of caffeine.
The same holds for tea. If you brew 8g of oolong the traditional way in a small vessel (gaiwan, Yixing teapot) and it will contain lots of caffeine. This is due to the high leaf-to-water ratio when brewing the traditional way: generally you steep twice a much tea in just about 4 oz (120ml) of water. In contrast, steeping a bag of tea in a large teapot, will result in less caffeine.
You may want to read our full tea caffeine guide to learn about all the factors affecting caffeine levels in tea.