johnaltieri 's List: Tea Nerd

• II. CAFFEINE LEVELS IN VARIOUS TEAS
  Another much-repeated claim is that black tea is high in caffeine, green tea is lower, and white tea (through the naturalness of its manufacture it is implied) has next to none. While suiting the sales pitch of some tea vendors this information is so wrong as to verge on the fraudulent.
  
  Three scientifically verifiable facts are:
  
  1. Caffeine level varies naturally in types of tea and levels in one type may overlap with another type
  2. 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%)
  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), and
  • during fast growing seasons.
  
  Thus tea derived from older leaf, China type seedling bush, under-fertilized husbandry and in autumn season will naturally be lowest in caffeine. Georgian and Turkish tea falls into this category: expect only 1 to 1.5% caffeine in them, compared with the usual 3% in retail teas. Tea from well-fertilized fast-growing young tips of African clonal tea can often have 5-6% caffeine.
• The natural complexing of caffeine in tea (it binds with tea polyphenols during steeping) gives a slower and more gentle uptake in the stomach and hence to the brain; and I suspect that the relaxing effect of tea's own mind-calming amino acid (theanine) also contributes to the body's reacting more gently to tea caffeine than to coffee caffeine.
• First and most importantly, let us remember that tea was designed by Mother Nature to have caffeine in it – indeed it is caffeine that is demonstrably the primary reason that tea (and coffee, cacao, and mate) became popular beverages.

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