Cleaning The Kettle by Cleaning The Kettle If you get a lot of calcium build up at the bottom of your kettle put about 300ml of white vinegar in the bottom of it, 2 slices of lemon and fill the rest with water to the top. Boil it normally and then tip it all out. Fill the kettle to the top again and boil it for the second time to get rid of the lemon and vinegar taste/scent. Tip it out again. Good as new!!! ☺️