A. For those of you who have never seen a tea cozy, think of it as a sleeping bag for your teapot. It serves two important functions. First, to get the most flavor from your tea leaves, you should cover your teapot with a cozy to keep the water at the optimum brewing temperature. Secondly, if you’ve brewed more than enough tea for one cup each, your cozy will keep the rest hot while you sip. Cozies that leave the pot handle and spout exposed are handy, but for full heat-keeping effect, choose one that covers it all. Practicality aside, whether your cozy is knitted, felted, stitched or quilted, it’s also another great canvas for self expression.