Say you want to order a low-caffeine tea. For years, common wisdom said white tea: Its delicate aroma, pale color just sounded like the perfect after-dinner sip. Not like black tea, with its assertive, jump-start flavor. So which is it? Look at the charts below:
On the left, black (red bar) and white (blue bar) tea get almost equal billing for caffeine content, while the chart on the right ranks white tea near decaf. So what’s the “right” answer, or more accurately, is there one?
Turns out it depends on the age of the leaf, time harvested, and processing method, just to name a a few variables. . Recent research has found that frisky young leaves plucked early in the harvest season have more caffeine than older one plucked from down on the stem. Real white tea — and there are a lot of bogus whites around — are young buds, minimally oxidized – and often have more caffeine than any black tea. Green tea is also minimally oxidized and can be somewhere in between, depending on when plucked.
What’s equally surprising is how brand and time affect the amount of caffeine in the cup. Caffeine is bitter and anyone who has steeped their tea too long knows the taste. In a study published in the Journal of Analytical Technology, researchers at U.Florida College of Medicine looked at caffeine levels in different brands steeped for 1-5 minutes. Consider Earl Grey: Tazo Earl Grey steeped for 1 minute had 30 mg. of caffeine and a jangling 59mg after 5 minutes, while Stash Earl Grey had 24 mg. after one minute and 47 after 5 minutes.In the green teas, Tazo China Green had 23mg. after one minute; Stash Green, had 16mg. (All the above were for 6 ounce cups.) And Exotica China White had 23 mg after one minute; 47 mg. after 5minutes, which is equal to the Earl Grey by Stash.
Another study by U. Massachusetts scientists found surprisingly low levels of caffeine in oolong. A recent study commissioned by Canadian tea company Camellia Sinenis and conduced by Montreal scientists at TransBioTech deepened the pot: Darjeeling Sungma harvested early in the spring (first flush) had one of the highest caffeine (58 mg) content while Autumn Darjeeling, harvested much later, had a third less (16mg). The authors attribute low oxidation as the reason for high caffeine of the first flush Darjeeling. As the leaves matured, the amount of caffeine decreased.
But what’s a consumer to do? If you want a low-caff tea, you can’t exactly go into a tea house and order 2nd flush Darjeeling, lightly infused or only a Taiwan oolong. Or maybe you can. But until tea houses and tea shops post caffeine content the way some cafes display calories, know that in almost all cases, tea has way less the caffeine of coffee and has the added benefit of L-theanine, which cuts the jingle jangle.