Cold-Steeping Green Tea

What’s the healthiest way to prepare green tea? Recently, in Taiwan, a new trend has arisen of cold-steeping tea. Not like iced tea, where you make it hot, then cool it down. But you start with cold water, throw the tea in, put it in the fridge for two hours, or just leave it at room temp.

Supposed to have less caffeine, reduced bitterness. And I’m sure it does; but cold water probably also doesn’t draw out many of the antioxidants, either. I mean, that’s the whole point of brewing tea with hot water, right? To extract all the nutrition. We shouldn’t just presume, though, and so scientists in Italy took it upon themselves to compare the antioxidant activity of hot- versus cold-steeped tea.

Here’s the data for hot tea. This is measuring the lag time before cholesterol oxidizes. You mix LDL—bad cholesterol—with an oxidizing agent, like copper in this case, and it takes about 28 minutes to oxidize. But you add tea, and the oxidants slow down the oxidation and increase the lag time. That’s a good thing. And, as you can see, oolong tea is better than black; green is better than oolong; and white is the best overall.

But this is the antioxidant activity for hot brewed tea. In a surprise upset, cold-steeped tea was even better. Significantly better. So much so that cold-steeped black may even be healthier than hot-brewed white.

Why? Well, the only thing they could think of is that hot water is so hot that it destroys some of the catechins, the antioxidants in tea. So, I no longer brew my tea; I just throw it in cold water. Saves time, saves energy, and we now know it’s even healthier!

To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by veganmontreal.

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• E. Venditti, T. Bacchetti, L. Tiano, P. Carloni, L. Greci, and E. Damiani. Hot vs. cold water steeping of different teas: Do they affect antioxidant activity? Food Chem., 119(4):1597-1604, 2010.

Image thanks to Brandon Heyer via Flickr

• antioxidants
• beverages
• black tea
• caffeine
• green tea
• nutrition myths
• oolong tea
• phytonutrients
• tea
• white tea