Is there somewhere I can find out how much caffeine ther si in various teas?
Is there an online vendor that reports the caffeine content for all or most of the teas they sell? I found 1 or 2 that had some information, but none that had it listed with each tea.
As I understand it, the teas ranked fro lowest caffeine to highest are:
Herbals (I know, not really teas) Greens Oolongs Blacks
Where do Puer-ehs fall?
I would guess that whites are close to greens, right?
However, on the few sites that I found that showed caffeine content, some of the greens were higher than most of the blacks.
about this subject. I'll just copy my post from there, so if anybody read it there, please forgive me for repeating it here.
There seems to be a lot of confusion about caffeine content in tea. Everybody is citing the same sources and everybody is repeating the mantra: "all green teas have a much lower caffeine content than black teas". While this is true for many green teas, there are - as usual - exceptions to that rule. In the end, you'd need to test each tea individually for its caffeine content.
There's one published source of caffeine contents of individual teas that I'm aware of (maybe you could post others if you know of any), find it at
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The list - although far from complete - is quite revealing. It lists the caffeine content of a "longjing" (almost everywhere advertised as a low caffeine tea) as 3.7%, while a "Nilgiri Indian Black" is listed with 2.3% caffeine content.
Although I think your order is generally correct (with white tea at the very low end), you see that the question is a little more complex. As to the listing of caffeine content with every tea on a vendor site: the cost of the analyses would be very high I guess and most likely, caffeine content differs from harvest to harvest (although I'd expect not quite as pronounced as between different teas). So testing would be continuous AND expensive. That's probably quite prohibitive to tea vendors, especially since most people don't care to know (or are happy with the mantra I mentioned above).
If anyone here has in-depth knowledge about this subject, please let me know!
Pu-erhs, at least for the shou and aged sheng, are post-fermented green teas. The variety of tea plant that pu-erh is produced from (C. sinenesis var. Assamica) is also different from most teas in the market, including, black teas. I'm guessing that the post-fermentation process reduces the caffeine content of the pu-erh tea, which I feel has quite a high caffeine content in its sheng form.
Actually, I mentioned this to a co-worker who pointed me at:
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which is an article about a home caffeine test that the Wash U medical school folks are developing.
The standard old-fashioned test is to mix with an oxidizing agent, then ammonia is added until a color change is seen. In the case of tea, you have to clear the tannins out by adding a little bit of portland cement first... the cement adsorbs the tannins and gives you a cup of clear liquid. These days with cheap mass spectrometry I don't think anyone bothers but there's no reason you can't do the caffeine titres in a kitchen at home. I don't know how specific it is for caffeine, though, and it may also detect other related xanthines at the same time.
One old engineering definition of portland cement is "A hydraulic cement made by finely pulverizing the clinker produced by calcining to incipient fusion a mixture of calcareous and argillaceous earths." How could anyone resist such a confection?
Try it. The cement and some tannins precipitate out, and you get a cup that tastes like tea but is completely clear. It is reportely a popular practical joke source on construction sites in the UK.
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