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I have been reading a great deal on the brewing of teas as of late. Who's to buy, how to prepare, how long to steep... This is a long blog, but a well-worth-it one if you are a tea drinker! After all my reading I truly believe that the best method for steeping is to boil the water, pour it over the tea bag, cover the cup/mug, and let it steep at least ten minutes. Why you ask? In comparison to a beverage tea, which requires a 4-6 minute steep, the recommendation of 10-15 minutes may seem long. However, in comparison to steeping times for Traditional Herbal Medicines (THMs) in the tea form, which are typically infused for 20-30 minutes or decocted (simmered) for 45-60 minutes, the steeping time is not long. This longer steeping time allows for more of the components in the herbs to dissolve into solution.
The water is the extraction solvent when you prepare a cup of medicinal tea - pour boiling water over the herbs, let them brew a few minutes and then strain and drink. But there's more depth to this water story! While the initial solvent is the boiling water, as soon as the plant's cell walls begin to break down and compounds enter the water, the water changes. It isn't just water anymore. Depending upon what compounds are first released, the water can become a mild acid or a mild base solution, which in turn affects the release of other compounds. The longer you let the herbs steep, the more components you will have in your teacup. Each new compound that is released changes the solvent's composition until full saturation occurs or until the reaction is stopped by removing the herbs from the solvent. This enables some compounds that are not entirely water-soluble to still be released into the water. This is why a sufficient steeping period is necessary to produce a complete, balanced extraction.
It is now generally accepted that herbs contain multiple active constituents that contribute to their
overall efficacy rather than a single "magic bullet" active ingredient. What happens when you remove an alkaloid (or several)? Is a vital link in the chemical chain reaction removed, therefore altering all further reactions? These are questions that, as yet, have no answers.
Two methods of decaffeination are allowed in the US. One process uses the solvent "ethyl acetate" to remove caffeine. However, this process also removes about 65% of the catechin polyphenols, the components thought to have the most antioxidant activity. The other process, 'supercritical fluid extraction,' uses carbonic acid gas, a.k.a. carbon dioxide (CO2), as a solvent at supercritical pressure and temperature to remove caffeine from tea leaf. This is the process companies are using when they state they use "spring water and natural effervescence." While about 95% of the catechins are retained with this process, about 80% of the acids in the tea are removed which may or may not play a critical role in the activity.
Makes you think about what's happening in your favorite mug... Huh... Later gang.