Quality black teas can last up to two years in a vacuum pack or tin/canister if you know when they were harvested. If not, store six months to one year. And remember, the five enemies of tea are humidity, air, light, moisture, and odor.
Uniquely Tea is a collection of tea related bits and bobs from here, there and everywhere, with the occasional 'one-for-the-pot' off-topic post thrown in for good measure.