A lot has been written about caffeine in tea and the different levels in different teas. Many have been written by people very qualified to do so, that is, tea chemists and medical researchers. So, as a bit of a public service to all you lovers of premium fine teas from China and elsewhere, we present a list of where to find this information. I have to point out before going any further, though, that you will want to take the information on some of these sites with a bit of caution. Wikipedia, for example, isn’t always 100% reliable, although they do their best to monitor entries for proper citings, etc.
So many articles on this topic are written in a way just to attract search engine bots and get the site to appear higher up in the results. We have weeded past a lot of those to get to the ones with the best and most accurate information. We’ve also skipped those “article mill” sites like About.com, HubPages, Buzzle, and eHow.com where people get paid by the click and are therefore motivated to write things that attract your attention but don’t always have good substance.
The Mayo Clinic is highly respected for their objective, scientific information on a variety of topics relating to human health. This article on their Web site compares caffeine levels in both coffees and teas (the information actually was adapted from the Journal of Food Science). The thing that will surprise many is their table showing higher caffeine amounts in green tea. So often people think that black tea has the most caffeine and most sources stick with this.
From Tea Chemist Nigel Melican
One of the best sources on caffeine in tea states:
- Caffeine level varies naturally in types of tea and levels in one type may overlap with another type
- Black and green tea manufactured from leaf from the same bushes on the same day will have virtually the same caffeine levels (within +/- 0.3%)
- For a given bush, the finer the plucking standard, the higher the caffeine level
Actual caffeine level in tea is highest:
- when the tea is derived from buds and young first leaf tips (thus white tea has a high caffeine level)
- when the bush is assamica type rather than sinensis (can be 33% higher caffeine, thus African black tea tends to be higher than China black tea)
- when the bush is clonal VP rather than seedling (can be 100% higher caffeine, thus new plantings in Africa are higher than old seedling plantings in Asia)
- when the plant is given a lot of nitrogen fertilizer (as in Japan)
- during fast growing seasons.
International Journal of Nutrition, Pharmacology, Neurological Diseases
As I said above, this site does their best to ensure accuracy, but the open format has caused some situations to arise in the past where pages were edited to meet certain goals. Their page on caffeine, however, is extensive and includes about 172 citations from a variety of reputable sources. Sadly, they lump all teas together on this page and give a range instead of breaking it down by tea types.
Some articles like this one tend to confuse the whole issue by including herbals and other non-teas in with teas from Camellia sinensis leaves. Others continue to promote black tea as having the highest caffeine content and white tea the least (it has been known for awhile now that the color of the leaves does not determine the amount of caffeine – it is more a matter of where they are grown and the varietal or cultivar).
One Final Note
While there seems to be some disagreement on the relative levels of caffeine in the different tea types, they all seem to agree that it is much lower than other sources such as coffee, Mountain Dew, Red Bull, and other beverages.