How much caffeine is in tea? Black, green, white, oolong and herbal compared
Every tea from the tea plant has caffeine, and the amount depends more on how you brew it than on whether it is black or green. Herbal teas from other plants have none at all. Here are the honest numbers, with the usual warning that they are ranges, not promises, because leaf, water temperature and time all change the result.
The numbers per 200ml mug
Black tea: about 40 to 70mg. Scottish Breakfast and Assam brewed strong for five minutes sit at the top of that. Earl Grey, Darjeeling and Lapsang are in the same range.
Green tea: about 20 to 45mg. Sencha and Gunpowder are towards the upper end, Genmaicha lower because part of the weight is rice. Jasmine Green and Chai Nana are in the middle.
Oolong: about 30 to 50mg for the first steep, less for each steep after.
White tea: about 15 to 30mg. Pai Mu Tan is one of the gentler cups.
Pu-erh: about 30 to 60mg, similar to a black tea.
For comparison, a mug of instant coffee is around 60 to 80mg and a shot of espresso around 60 to 75mg. A filter coffee can be over 100mg.
What changes the amount
Time matters most. A three minute brew pulls out much less caffeine than a five minute one. Water temperature is next, which is partly why green tea brewed at 80°C comes out lower than black tea brewed at 100°C. More leaf means more caffeine. Broken leaf, like the CTC in Assam, gives up its caffeine faster than whole leaf.
The old tip that a 30 second rinse removes most of the caffeine is a myth. It removes some, maybe a fifth, and takes a lot of flavour with it.
The teas with no caffeine at all
Rooibos, Rooibos Kalahari, Honeybush, Peppermint, Chamomile, Lavender, Nettle and Crimson Berry are not from the tea plant and contain no caffeine. Not low, none. That makes them the ones for the evening, for anyone who is cutting down, and for children.
Rooibos and honeybush are the closest in character to a normal cup of tea, which is why they make a good late night switch. Rooibos Kalahari is my own evening tea.
Decaf tea
We do not stock decaffeinated tea. Decaf tea is made by processing the leaf to remove most, not all, of the caffeine, and it usually loses flavour on the way. If you want a tea plant taste with less caffeine, a white tea or a short brewed green is the honest route. If you want none, rooibos or honeybush.
A note on how this feels
Tea also contains an amino acid called theanine, which is part of why a cup of tea feels different from a coffee with the same caffeine. I am not going to make claims about what it does, but most people find tea a steadier lift. Try a strong Assam next to an espresso and judge for yourself.