It appears we have been taken in by a popular Internet myth. A reader comment (Thanks, Laura!) brought alerted me to an excellent post on tea myths and includes findings from (apparently) the only two studies to every test this methodology of reducing caffeine levels in tea. These show that the reduction from a short steeping would be more in the 9-20% range, as opposed to 80%. To achieve 80% the steep would have to be over 5 minutes. It’s an interesting article, worth a read–it also addresses the complex subject of how much caffeine black and green teas actually have.
I’m not sure if this is common knowledge or not– my acupuncturist told me about it years ago–but you can decaffeinate your own tea.
As someone who loves (loves loves) hot black milky tea, even in summer, but who no longer gets along well with caffeine, this is a very good thing. Commercially decaffeinated tea is indistinguishable from dishwater. The DIY version doesn’t taste as good as “real tea”–the undiluted kind– but it’s better than the store bought stuff.
An additional advantage is that you don’t have to stock two types of tea–one type becomes two, saving shelf space. Note that this works best with loose leaf tea, but can be used with bagged tea, too.
All you have to do is brew your tea as you normally would, but start counting as soon as you pour the hot water. After at least 30 seconds but no more than 1 minute you pour off all of what has brewed so far. And yes, that’s all the good stuff.
But by doing so, you are pouring off about 80% of the caffeine. It’s sad, but being all headachey and jittery is sad too, so I do it. Then you top off the tea leaves with fresh hot water and start the brew again. This one you drink.
Commercially decaf tea is lower in caffeine than this homebrew–just to be clear. According to the Mayo Clinic, one cup of commercial decaf black tea can contain anywhere from 0 to 12 mg of caffeine. A regular cup of black tea ranges from 14 to 70 mg.
With this DIY process, a 70 mg cup would be reduced to 14 mg. A cup of regular green tea ranges from 25 to 45 mg, and can be decaffeinated by this method as well.