Can caffeine be rinsed from tea?
A quick rinse of the tea leaf once before making a cup can reduce the caffeine content of the tea. True or false?
If you are a caffeine-sensitive person who loves tea, you might often have been offered this work-around - rinse the leaves for a quick 30 seconds, and only then use the leaf to make your cup.
Turns out this prescription is erroneous.
I was recently asked again about this practice by a customer, and it was a bit frustrating that I did not know the answer for sure.
So I turned to the experts, and I was pleased that Nigel Melican, a tea industry veteran, founder of US League of Tea Growers and currently holder of the honorary chair at the Tea Research Association of India, decided to help me with the answer by pointing out to an article he had written exactly on the same question nearly eight years ago.
Referring to a 1996 scientific study done in Canada, published in Food Research International Vol 29, Melican asserted that the scientists had studied the caffeine extraction in tea and the results were very different than that proffered by "common wisdom."
Authors of the research Monique Hicks, Peggy Hsieh and Leonard Bell had used the High Performance Liquid Chromatography (HPLC) method to study the precise time related extraction of caffeine from tea leaf. They used six different teas, including black, green and oolong, three in teabags and three in loose leaf form. The results were published in a peer-reviewed paper, "Tea preparation and its influence on methylxanthine concentration," tea caffeine being one of the prominent methylxanthines.
The results that emerged from the study were as follows.
30 seconds: 9% caffeine removal
1 minute: 18% caffeine removal
2 minutes: 34% caffeine removal
3 minutes: 48% caffeine removal
4 minutes: 60% caffeine removal
5 minutes: 69% caffeine removal
10 minutes: 92% caffeine removal
15 minutes: 100% caffeine removal
This meant that a 30 seconds quick rinse would still leave 91% of caffeine in the leaf. And if you wanted to cut the caffeine strength by half you would have to steep at least 3-4 minutes. Needless to say there would be no "tea" left if the tea was rinsed for 3 minutes! And if you had to get rid of all the caffeine, it seems you'd have to steep for 15 minutes. To make tea after a 15 minutes steep would be a case of dead-on-arrival.
Melican looked at more other studies and they all pointed to the same thing.
So this practice of rising tea to reduce caffeine is as Melican puts it nothing but an "internet myth". It does sound plausible when you hear it first. But in the light of scientific research it has been proved to be an erroneous idea, just like the other persistent one that black tea has more caffeine than green or white tea.