Caffeine is a naturally-occurring chemical that plants use as both an herb- and a pesticide. Caffeine in the soil around a tea plant (from leaf-litter) will inhibit the growth of other plants that may compete for resources. Additionally, some non-beneficial insects are affected by the caffeine in such a way as to keep them from nibbling in the future. In humans, caffeine is a mood-elevator and a stimulant (both mentally and metabolically). Caffeine’s effectiveness is increased by steeping its naturally-occurring element (leaf, bean) in water.

When caffeine was first discovered in tea, it was named “theine” which I don’t know how to pronounce (teen? tee-een?). It was eventually discovered that it was, in fact, the same compound as the caffeine found in coffee. Personally, I have noted different effects from caffeine vs. theine (or even mateine), and though there is no scientific evidence for this (that I could find), it may be due to other compounds in the liquid.

Theine (which I’m essentially using for clarity’s sake, with the understanding that it’s the same as caffeine) is accompanied by theobromine (in lesser amounts than are found in cocoa). Some of tea’s antioxidants may also cause theine to be metabolized differently. (Mateine, which I’m totally not making up, can similarly be said to be accompanied, in its natural state, by additional compounds that may cause it to affect the drinker differently than caffeine does.)

Caffeine (most of the studies done either use coffee or straight caffeine) is metabolized through the intestine (rather than through the cheeks, like sugar is), so its effects are not as immediate as some drinkers might guess. Its effects can be noticed to wane after about 3-4 hours, depending (on age, sex, weight, and probably on regular dosage). Caffeine readily crosses from the blood to the brain, and causes spiders to work faster but much less effectively. I guess it’s easier to tell the results of this kind of test in spiders, but aren’t rats at least mammals?

Socially, of course, caffeine is very important in today’s society. Around 90% of adults consume it daily in the US and I’m three of them. Caffeine tolerance and withdrawal are similar to those of most similar drugs and it’s actually relatively easy to build a tolerance. Caffeine addiction may be closer to an addiction to the taste, breaks, or ritual of the drink itself. The act of drinking tea is a subject for a whole nother post, but is also very socially important. Then, of course, there’s the LDS reaction to caffeine: the Word of Wisdom states that “hot drinks are not for the body or belly”, which is quite sound advice and could be paired with “cold drinks”. Extremes of either side are deleterious to the digestion. The Word has been promulgated as pertaining to coffee & tea, but apparently does not include decaffeinated or herbal teas, which might still be “hot”.

Which brings us to…decaffeination!

I was actually in Teavana today, browsing, as I am wont to do, and picked up a book that outlined the two major ways of decaffeinating tea. The third way, which is suggested for home (but which is impractical for industrial) use is simple: fix some tea and let it steep only for about 45 (30-60) seconds, then pour out this water. Allegedly, 80% of the caffeine will be taken away. In my experience, so will at least 50% of the taste. But to each their own. [This is what the book claimed; Wikipedia says that a 5 minute steep will release 1/3 of the caffeine.]

The absolute worst way to decaffeinate tea is to steam the leaves and then soak them for a long time in methylene chloride. In order to remove this solvent, additional steaming is required for the same amount of time as the soak. Most teas will retain about 10% of the solvent, which then of course, gets into your tea water & eventually you. I don’t know what they do with the solvent after it’s been used, if it can be reused, or anything else, but it doesn’t sound like a generally happy process, for either the tea or the factory. Tea decaffeinated in this manner also loses much of its healthy properties (antioxidants & such).

The second industrial way to reduce the caffeine of tea is to soak it in a solution of CO2. The environmental impact of CO2 is debatable, but it is generally accepted to be the healthier means (in terms of the health of the drinker). Imported (decaffeinated) teas to the United States are required to use this method. I have no information regarding non-imported teas; obviously the US is not a well-known tea-grower, but it may be the case that the methylene chloride means is acceptable if performed within the country. Tea decaffeinated in this manner retains its healthful qualities and ingesting CO2 is not going to cause the drinker any harm.

My personal suggestion is that, if one is drinking tea in the afternoon (and so would not want to have a lot of caffeine), stick to green or white teas, which have less caffeine anyway. If drinking tea in the evening, an herbal tea or rooibus may be best. If drinking tea for religious reasons (or rather, not drinking it for those reasons), you can decaffeinate your own tea to some extent, but there are not generally many high quality decaffeinated teas.