Thursday, April 14, 2016

Gongfoolery: The Effect of Heat Part 2, A Tea Experimentation

Last Week's Gongfoolery post looked at the effect of preheating porcelain brewing equipment, for this week I am keeping the same concept but switching up brewing equipment, going for clay this time around. I mulled about how to do this, not sure if I wanted to use Yixing since depending on clay type and firing the results could be very different, but I lacked Yixing cups to match, so the affect of heat on Yixing will have to wait until after I do a bit of shopping someday in the future. For this experiment I am using my Petr Novak clay pot and a mostly clay cup from, I say mostly, the very bottom is glazed but the rest of the cup is clay. Like before I will first test as a control, not pre-heating either the cup or the teapot, then I will pre-heat the teapot but not the cup, and then I will preheat the cup but not the pot, lastly I will pre-heat both of them.

Using a tea I have been drinking a lot of lately, Yunnan Sourcing's Wu Liang Hong Mao Feng Yunnan Black Tea (spring of 2015 harvest) the control went as expected. Clay is an interesting thing, it holds heat so well, this has pros and cons, pros being my tea stays warmer for longer...cons are the inevitable burnt fingers. I do notice that using a clay cup brings out the underlying mineral qualities of this tea ever so slightly.

Next onto the pre-heated teapot. Waiting for the cup to cool down was exciting, and by exciting I mean long winded. Good thing for Ark entertainment. Like with the preheated gaiwan, the aroma of the tea is more pronounced inside the teapot, the leaves being heated makes them more fragrant, also the smell of the clay is more pronounced as well. I noticed first off that the initial steeping is more robust and nuttier, really taste the roasted peanut and yam notes of the tea that are usually a tiny bit faint at the first steep. Since the teaware is pretty well heated by the subsequent steeps (unless you forget about the tea between steeps) then the real noticeable change is on the first steep. Fun little side fact, I do frequently preheat this teapot (and my yixings) because I find that the underlying mineral qualities are quite lovely. However I do not analyze the aroma of the leaves for a review, that way involves me stuffing my nose in the leaves, since the aroma of the leaves in the pot is subtly different than outside being breathed on.

Again I needed to wait a while for my teaware to cool down, this is something that is very important with clay, it puts porcelain and glass to shame with its ability to stay warm for so long, it is one of the reasons you frequently see advice to not use clay for green teas. I of course took this advice and tossed it out the window, partially do to admiring many Japanese clay teapots made for Sencha, it works fine, though I can certainly see the reasoning behind it 'pro' tip, leave the lid off if brewing greens in clay. Ok, my pot has cooled and the experiment can commence! The preheated cup is similar to the control, the first steep is subtle, more sweet and with underlying mineral qualities. Also I notice the mouthfeel is smoother than the control, which seems to be the big difference when pre-heating the clay cup.

The last test, as expected it is a blend of the previous two. The taste is richer, the notes of of peanuts and yams more standout, and of course the mouthfeel is smoother. I found the changes between pre-heating and not pre-heating to be more dramatic than with porcelain, in a very positive way at that. Clearly my next test needs to be whether or not heat affects things based on shape, is the round more closed environment of the teapot more effective at heat making a difference than the wide open gaiwan? Next week I will be finishing out my section on heat pitting a yixing pot and a yixing gaiwan against each other.


  1. Incredibly fascinating observations thus far. I look foward to the next installment. Have you thought about approaching NPR to cover this topic? I'm thinking of NPR's Tea Tuesday as well as Science Friday hosted by Ira Flatow.

    1. Ooh that could be fun! I shall have to give that some serious thought!