How does the brewing process affect taste?
And why did I major in music instead of something useful like chemistry?
I’ve been exchanging emails with Louis Kaplan, a friend who’s a Senior Research Scientist at Stroud Water Research Center. Like I said in an earlier post, I’ve lately understood the brewing process as an interplay between different water temperature ranges. If you increase the proportion of time at one temperature range, you maximize the solubility of one particular component chemical, and thereby one aspect of flavor.
So the graph above reinforces my opinion that “dissolved oxygen” has little to do with the taste of tea. Boiling water just can’t support any dissolved oxygen. And even if you take the kettle off a bit early, there still isn’t much to be salvaged.
But his email was discouraging, in that he said:
I think your underlying question is very complicated – what are the properties of the various constituents in tea and how do the parameters of the infusion process (temperature, contact time, tea to water ratio) influence the properties of the extract. I don’t think this is a question that you will answer from tables of solubility. More likely, this is a lifetime of exploration, some of which has no doubt been done by tea purveyors with access to sophisticated analytical instruments and the budget to run them.
I was afraid of that.
But Louis did send me a Materials Safety Data Sheet for epigallocatechin gallate, which I’ve linked here. You’ll note under Section 8 that you are not supposed to take it internally. “Facilities storing or utilizing this material should be equipped with an eyewash facility and a safety shower.” Does your local tea bar take adequate precautions when handling green tea? Do they at least use safety goggles and latex disposable gloves?