Data point...

[alexpgp]

Samarkand "No. 95" green tea, which I bought some time ago at the market in Baikonur, can stand being left to steep for just about ever without turning bitter. This, in contrast to fairly expensive stuff I've bought from the folks at Teavana.

It may be that this lack of bitterness is an indication of poor quality tea, but I can drink it without wincing if it's steeped for a while, which makes it a winner as far as my (potentially taste-challenged) tongue is concerned.

Cheers...