I picked up a green tea from Tim Hortons today, primarily because I couldn't get to my favourite tea shop (LM Teas in Niagara Falls). At the first sip, I began regretting my choice. Not because it was undrinkable, but because I've had so much better tea.
First off, Tim Hortons staff don't seem to know diddly-squat about tea. Some would say they don't know anything about coffee either...but we'll stick to tea. Two bags of green tea in a cup is enough to turn the tea so dark it might be mistaken for black tea. In addition, it makes it so strong and bitter that while it does an admirable job of keeping one awake (perhaps its only redeeming feature), it's rather unpleasant to drink.
I wonder if Tim Hortons staff ever drink green tea. I strongly suspect they don't. One of the reasons their tea gets so bitter, I believe, is because they're using boiling water to make it and then they're allowing it to steep for longer than it should. High water temperatures bring out the bitterness in green tea and letting it steep too long is another evil they could avoid.
According to the folks at LM Teas, the idea water temperature to make green tea varies on the variety. Some teas can be brewed starting at 50°while others do fine at 80° to 90°. Again, it depends on the tea. Perhaps Tim Hortons tea is specially picked to be made with scalding hot water. I'll have to ask.
Anyway, if you're in Niagara Falls and need a good cup of tea, I recommend my friends at LM Teas. With over 200 varieties of loose-leaf teas, you'll find something you'll like.