Nothing ruins a tea party faster than a gross stain or a foul taste in the Earl Grey. Fortunately, teakettles and teapots are easy to keep clean with the proper technique. The two main enemies are: tea stains and mineral buildup. Mineral buildup usually afflicts kettles used for boiling water, while tea stains usually afflict teapots used to steep tea.
Cleaning Mineral Deposits
Stainless steel and copper teapots are generally impervious to tea stains, but they are vulnerable to scummy deposits. Tap water contains minerals such as calcium, and repeated boiling can leave behind evaporated minerals inside the kettle. The minerals form a white film that looks a bit like soap scum. The easiest way to remove these deposits is with a mild solution of vinegar and baking soda. The step-by-step solution:
Pour fresh water mixed with 2 tablespoons of vinegar and 2 tablespoons of baking soda into the kettle. Fill up the kettle to about the level you would for making tea.
Bring the solution to a vigorous boil and keep it boiling for about half an hour. Keep an eye on the kettle to make sure it doesn't boil dry.
Wait a few minutes for the water to cool.
Use a soft pad or a sponge. Avoid using abrasive pads as these may scratch the metal.
Rinse the kettle several times to avoid leaving a lingering vinegar taste in your tea.
If you notice mineral deposits on the outside of your metal teakettle, use the same technique to remove them. Just fill your sink with a combination of warm water, baking soda and vinegar. Soak the kettle in the solution for a few minutes, and then scrub away.
Attacking Tea Stains
China and glass pots require different cleaning techniques. Since you aren't boiling water in these pots, you're unlikely to have much trouble with mineral deposits. Instead, you'll probably be dealing with tea stains, and the best approach for removing tea stains is to use fizzing denture tablets. The denture tablets are a mild but tough detergent designed to remove stains from false teeth, and they're available in any drugstore.
Simply fill your teapot with very hot water and add a denture tablet to the mix. Let the water sit for at least an hour. Then pour out the mixture and wash it with soap and water. If the stains persist, try it again with two or more denture tablets and let them work overnight.