I am a copper fanatic! I've tried numerous cleaners/polishers and ran across this old-time recipe - lemon juice and salt. The citric acid has a chemical reaction with the patina and turns the copper shiny again. This flea market find started out almost black (I forgot to take a photo, but have one that really needs to be polished). I use a paper towel lemon/salt mixture for basic cleaning and an soft toothbrush for the tough spots and hard to reach spots. No harsh chemicals and almost always in the kitchen!