Copper oxide dissolves in a mixture of weak acid and table salt, both of which are found in ketchup. Slather the ketchup onto your copper-bottomed pots and leave it on for as long as you can. Then wipe and rinse. (By the way, you get the same result with lemon juice plus salt.

How long do you leave ketchup on copper to clean it?

Copper pots, pans, and kettles are beautiful and preferred by many chefs. However, they can easily tarnish. Spread a layer of ketchup over the copper and let it work for 10 minutes. Rub with a soft cloth and rinse well.

Does ketchup clean copper?

"You can use ketchup and spread it all around the copper. The acid in the tomatoes will remove the tarnish. After rubbing it all around the item, make sure to thoroughly rinse."