Caffeine & Tea

To learn about caffeine and tea, we have to start with breaking down a few concepts:
a) Decaf?
b) Teas with or without caffeine
c) Teas that deliver caffeine differently
d) Caffeine's effect on unique people

a) Decaf tea is a strange concept. The simple explanation is that when you are buying decaf tea, you are buying tea that has been used, dried again and then resold. Certainly not an appetizing concept, but the long and detailed explanation is a lot less appetizing and involves either a process called supercritical fluid extraction (simplified to soaking the leaves in a bath of liquid CO2 [carbon dioxide]) or a direct method involving a steaming and soaking in methylene chloride or ethyl acetate solution for many hours. The results are the same regardless. The process certainly started off with poor quality tea leaves that we would hesitate drinking even before the added decaffeination. But after the added processing, calling it tea any longer is stretching it!

b) But certain teas have caffeine and other do not, right? It is a bit more complex than this simple statement would imply. Caffeine is a natural byproduct of the natural tea leaf (camellia sinensis), just as it is with the coffee bean. In fact it is really a natural chemical derived from the soil itself. This inherently means that there is no real tea leaf that is caffein-free. However, certain soil compositions will produce more or less caffeine, and unfortunately the control of caffeine-producing soil properties is not yet a hard science. So a tea production during one single season might have a radically lower caffeine content than previous years, but this is unusual and also definitely not constant. Perhaps in the near future there will be more studies to show which fertilizers can better control caffeine content in the soil composition. A second and separate factor to caffeine content in the tea leaves is actually the age of the tea leaves used in the tea production. So younger tea leaves, such as those that are used in quality green teas will have a significantly higher caffeine content than Pu'er teas, which are much more common containing fully mature tea leaves; oolong teas are similar to Pu'er though slightly less so.

c) As closely related to the previous explanation, some teas appear to create less of an effect when delivering the caffeine. Our best explanation for this is that it is due to the processing techniques. Two tea categories specifically come to mind here, white tea, and mid/high-roasted Wuyi oolongs. The white tea production technique is much more well-known for creating a tea that simply appears to leave little or no caffeine in the tea infusion even with a strong steeping. In fact this is a tea which we often hear of people drinking to calm their body and head off to sleep! Wuyi oolongs are a bit different since they are more varied and exist in so many sub-species and production methods. Within a normal range of quality Wuyi teas there is a basic classification for the style of roasting, with terms like Light-fragrant (qing xiang), mid-roasted (zhong huo) and high-roasted (zu huo), which basically represent low-level firing all the way to very roasted (zu huo). From our experiences with these teas, the mid and high roasted teas release far less caffeine into the tea than their light-fragrant derivative.

d) All this being said, however, and we can acknowledge that caffeine response is a highly personal thing! Each person is in fact unique and each will have their own tolerance and threshold for absorbing caffeine. While one person will be up all night after a sip of green tea, another might not even feel any change whatseover. The point of all of this is: Decaf is not an option; some teas might be a great way to drink without the caffeine -- but in the end it is dependent on each persons' metabolism. Enjoy and keep drinking tea anyway!