Tuesday, December 28, 2010

Brewing the Perfect Green Tea: Best Brewing Time and Temperature for Optimal Potency

Here is something for all of you who have always asked themselves how to prepare their tea to "get the most out of it". Well, I know normal people would go by taste, but are we normal? No! We want maximal antioxidant-content and a decent amount of caffeine to jack us up and this is where the results from a recent study (Ziaedini. 2010) come into play.

The scientists from the Iranian Institute of Research and Development in Chemical Industries investigated the effect of different brewing times and temperatures on the amount of antioxidants and caffeine you'll get in your tea. Here are the results (cf. table 1):
Table 1: Diffusion coefficients of catechins and caffeine obtained for conventional extraction of green tea leaves.
Obviously it takes a decent temperature of ~70°C to achieve maximal diffusion of the constituents in the short and in the long term. In spite of that, a close look at one of the graphs (cf. figure 1)
Figure 1: EGCG content as a function of time for different water temperatures in °C
shows that even with decent temperatures (>70°C) it takes some time for the antioxidant content (in this case the infamous ECGC content) to achieve significant levels - and lets be honest, do you like, or even, can you really drink a tea that has been brewed for 10 or even 20 minutes? If you can, you're the man (or woman) - if not you probably better buy some capped extract ;-)