Decaffeination Myths Are All Washed Up

While there are certain tea preparation methods that require a rinse of the leaves, decaffeinating isn't such a method.

That doesn't stop it from being a common, and oft repeated, myth:

Rise your leaves for 30-45 seconds and that decaffeinates them 80-90%.

You'll still find tea sellers repeating this to customers, and friend telling friends. Like so many other myths, it's pervasive and people want to believe it.

Thanks to those in the tea industry who are committed to knowing the truth, (in particular Nigel Melican of Teacraft, and in general the committed members of the Teamail list) we have this piece of scientific enlightenment:

After some intensive Internet trawling (nay, dredging) and poring over a mish-mash of half truths and myth (and some of my own caffeine data regurgitated without attribution or comprehension) I have now found the level of data that I was advocating earlier this week - a peer reviewed scientific paper recording precise time related extraction of caffeine from tea using a modern detection technique (HPLC). This paper "Tea preparation and its influence on methylxanthine concentration" by Monique Hicks, Peggy Hsieh and Leonard Bell was published in 1996 in Food Research International. Vol 29, Nos 3-4, pp. 325-330. (FRI is copyright of the Canadian Institute of Food Science and Technology).

In summary Hicks et al measured the caffeine and theobromine (total methylxanthine) content of six different teas (three bagged and three loose leaf, including black, oolong and green types). They measured caffeine extraction in boiling water at 5 minutes, 10 minutes and 15 minutes. They replicated all their extractions three times to eliminate error. Extrapolation of their data gives the following caffeine extraction percentages below 5 minutes (averaged over all tea types and formats; note while loose tea extracted marginally more slowly than teabag tea it made only a couple of % points difference):

30 seconds 9%
1 minute 18%
2 minutes 34%
3 minutes 48%
4 minutes 60%
5 minutes 69%
10 minutes 92%
15 minutes 100%

This is very much at odds with the mythical "30 or 45 second hot wash to remove 80% of the caffeine" advice - as a 30 second initial wash of the tea will actually leave in place 91% of the original caffeine!

(Thanks to Nigel.)

Green tea has it's own caffeine myth: green tea has less caffeine then black.

Each tea has it's own caffeine level, with different amounts ending up in your cup, based on the leaves, the processing and the preparation in your pot. Some greens have more caffeine then certain blacks. It also serves the drinker to remember that decaf isn't caffeine free, it's simply a lower level of caffeine - some still remains.

While many of us enjoy, need or crave a caffeine kick to others it's a health hazard. These are dangerous myths for those who are cutting back on caffeine for health reasons.

Good ways to truly lower caffeine levels in your cup:

• Select teas that have tea and herbal ingredients (Sloth Tea, Carol's Tea and Day Dream are all excellent low caffeine choices)
• Go with something completely herbal (like Refreshing Afternoon or Hibiscus Mint) or based on rooibus

The good news for caffeine addicts: you'll still get your caffeine kick on the second and third infusions.

Felicitea believes you should know what's in your cup - a well informed tea drinker is a happy tea drinker.

(For more info, and a fascination conversation in the comments, check out this full article over at ChaDao by Nigel Melican. Thanks Brandice!)