I have a couple of tea bottles I alternate between at work. There’s the Lock & Lock and the generic one (it’s like this one: http://amzn.com/B001KW03I6 ). I realized that this tea really doesn’t like the generic bottle. There’s just not enough room in the basket for the leaves to expand. So the tea ends up kind of astringent, unlike in the Lock & Lock where they float around freely like some strange species of green seahorse.
So if you’ve tried this and found it too heavy or astringent, give it some room to swim around. It’s much better that way.