the german tea expert Ernst Janssen recommends to also use boiling water to prepare green tea as most of the teas are contaminated with germs and other things. different green tea brands including organic tea brands were tested by the renowned German test.de magazine and they confirmed that, also most of organic teas are contaminated. and since this is nothing you can easily check at home, better use boiling water. h…
That seems paranoid considering that I have never heard anyone getting food poisoning from tea, no matter how it was brewed. edit: Reading the linked article, it seems mostly concerned about contaminants and not germs. Intuitively thinking, I'd imagine higher temps would end up extracting more of those from leaves to the drink than lower temps?
As for boiling tea for sanitation, I took a wilderness first responder class and they taught us that you could bring water to a boil at any altitude a human can breath at (without holding it at a boil for 15 minutes as some claim) and it's considered sterilized. In Cusco, that would be around 191F/89C (humans can breathe quite a bit higher up than Cusco). Not a bad tea-brewing temp!
Also, I suggest trying kukicha. It's high in l-theanine and lower in caffeine. Tasty too.