In areas with hard water or heavy lime in the tap water, deposits may form in kettles and other implements used to hold or boil water. This lime scale is white and may become thick enough to flake off if not removed. Metal kettles are most likely to develop this scale. While chemical descaling products are available, there is no need to waste money on them. Use common kitchen ingredients to easily descale your kettle with little effort. Descale regularly before the build-up becomes extreme, otherwise it may take more than one cleaning to get rid of it all.
Rinse out the kettle if it has boiled anything other than plain water, such as tea. Fill the kettle with one part water and one part household vinegar.
Set the kettle on the hob and bring it to a boil. Turn off the heat once it boils, then let it sit on the hob overnight.
Pour out the vinegar and water in the morning and wash the pot with a dish scrubber to remove the rest of the scale. If lime scale is still visible, replace the vinegar solution and boil a second time.
If you don't have vinegar, fill the kettle with ¼ cup lemon juice then fill with hot water. Let sit overnight then scrub out the lime scale. Remove lime scale without boiling. Fill with the vinegar solution and refrigerate the full kettle overnight. This also removes the scale if it isn't too severe.
Avoid letting the water boil out of the kettle, as this is more likely to form scale and it may ruin the kettle. Do not use vinegar in glass kettles or glass coffee perkers. Instead, use three tablespoons of baking soda in a kettle filled with water, boil or perk, then rinse.