Decaffeinated Tea

Wikipedia: Decaffeination
Last Updated: Mar. 21, 2012Decaffeinated tea, usually called decaf, is tea that has had the caffeine removed. Decaffeinated tea is distinct from naturally caffeine-free herbal teas. Decaffeination is imperfect; although most of the caffeine is removed, some remains (typically around 1-2%, although more can remain). On RateTea we denote Decaffeinated teas by , whereas naturally caffeine-free herbal teas are labelled .

Decaffeinated tea usually suffers from inferior flavor. People seeking caffeine-free tea-like beverages but unsatisfied with the quality of decaffeinated tea might consider exploring rooibos or any number of other caffeine-free herbal teas. Also worth considering, decaffeinated scented and flavored teas are often more enjoyable than decaffeinated pure teas, because the flavoring and blending can be added after the decaffeination process has been carried out, leaving the additional flavors fully intact.

Different methods of decaffeination:

Decaffeination can be carried out by a number of different processes; some of them are safer than others, and they also have different impacts on a tea's flavor.

CO2 - This method involves using carbon dioxide which has been compressed into a supercritical fluid. This method has the advantage that it uses only carbon dioxide as a solvent, which is completely non-toxic. It is good at preserving flavor and its main downside is that it is expensive.

Ethyl acetate - Ethyl acetate is an organic solvent commonly used in decaffeination. It is naturally occurring, both in fruit and in tea leaves, and has a low toxicity. Ethyl acetate tends to remove more flavor from tea than other decaffeination processes.[2]

Methylene chloride - Another decaffeination process involves methylene chloride, a chlorohydrocarbon, also known as dichloromethane. This process leaves small traces of the chemical within the decaffeinated tea leaves. Methylene chloride is toxic, and it has been shown to be carcinogenic in animals. This method is legal in the US but regulated by the FDA. Companies selling tea that has been decaffeinated by this process usually do not bring attention to it because of its bad public perception. The amount of the solvent remaining in the finished tea leaves, and the degree to which it poses a health risk, is a matter of dispute. One article advocating for its relative safety claimed that the concentration in tea is less than 1ppm [3], but an older study of decaffeinated teas found levels as high as 15.9ppm[4], beyond the US FDA's allowed threshold in food products.

Discontinued (historic) processes - Ludwig Roselius invented the first decaffeination process, which involved benzene. Benzene was later found to be toxic and carcinogenic, causing global health problems even in low quantities. Later processes involved trichloroethylene, which was discontinued after it was found to cause liver tumors in mice.[1] Fortunately for tea drinkers, the history of decaffeinated tea is relatively younger, especially in the U.S., and these unsafe processes were used primarily for coffee. Decaffeinated tea was first sold in the U.S. by Bromley Tea, which was founded in 1981, after trichloroethylene had been discontinued.

Other methods: Other less common methods of decaffeination include one using orange-peel extract.[1]

Can I decaffeinate my own tea with water?

In general, no. There are numerous blog posts claiming that most caffeine is extracted in the first 30 seconds or so of infusing a tea, and that brewing the tea briefly and discarding the water can be used to remove most of the caffeine. This technique does not work well because caffeine tends to diffuse together with flavor. For finely broken teas, this technique removes most of the caffeine but leaves little flavor. But with whole-leaf teas that retain their flavor longer, significant amounts of caffeine remain in the leaf even after longer infusions. For a safe bet, buy decaf tea, naturally low-caffeine teas, or caffeine-free herbal teas.

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