Cold Brewed [Steeped] Tea

In passing with another tea person I know I had a brief although provocative conversation.  I mentioned that I was drinking some Cold Brewed Keemun I made for a party I hosted, and his initial reaction was that it was a waste of good tea.  I a bit shocked at the somewhat up front condemnation of how I was drinking this tea, decided to ask him more about what he meant, and the conversation that followed had some rather illuminating points on how do deal with bad tea, and as sort of the other side of the coin, how not to treat good tea.

Before I go to far let me say, when I defended myself by telling him this particular tea I actually had a hard time drinking warm, due to its incredible potency and general astringency, he conceded that cold brewing may be the way to go with that tea.  Though it is a bit amazing, Iced tea is not a foreign concept in the United States, I do not know to what levels it has caught on in other countries, but at the same time brewing tea cold, and drinking tea cold is sort of a bait and switch with pretty much any tea.  There is one somewhat clear guideline that makes perfect sense and no sense at the same time depending on how you think about it:

Bad tea often make good iced tea, while good tea seldom makes good iced tea.

Its a bait and switch/ role reversal with tea when you switch from hot water to cold water.  Now there are ways to make incredible cold tea with good tea leaves, but they often require so much leaf, or give so little liquid that they don't seem worth while.  For some reason for tea to taste like tea we need that slight astringent and bitter aspect to the brew, which bad teas often have too much of, and good teas often have just enough or a little less than enough allowing us to add more leaf and get that much more in terms of extra flavors from the leaves.   

Queue the heat,  tea brewing 101 quickly establishes a correlation between both steep time and temperature with overall astringency of the brew.  Temperature is the biggest factor though, as a lot more time is needed once the temperature starts to drop. I am sure all my chemically and biologically oriented friends could offer richer more scientific explanations of the processes involved, but the general idea is the hotter the water the quicker and more readily compounds get from the leaf into the liquid.  Now these items diffuse at different rates depending on the temperature, and  the ones that diffuses very slowly at low temperatures are mostly the same compounds that cause the astringent/ bitter tastes to develop in the brew. As such cold temperatures and long steeping times get the most out of the wide variety of flavors in the tea, with the least amount of bitter components.

Why not good tea on ice? This one is probably harder to explain, as in a certain sense if we think of astringency solely as a bad item, it should not make sense. But I maintain that a bit of astringency is what makes tea what it is, and helps highlight its overall taste.  As such if you take a tea already low in those compounds and brew it in a way that further reduces the amount of those in the brew, you can often be left with a liquid that may smell nice, but taste very simple and bland.  (It is almost like astringency is the spices of the tea world, while the base ingredients may be great, typically they perform their best with a little extra spices to bring them to life). 

Other years I may have thought this is a very timely post, but I am living in an area stuck in perpetual winter, and I can only dream of eventually seeing warmer days ahead in which I'd love to reach for a glass of iced tea.