Copper pots and pans should be cleaned regularly to keep their original shine. Copper oxidizes over time and gradually takes on an allover dark colour that customers appreciate and maintain. To bring out its original brilliance, use a cloth dampened with a salt and vinegar or salt and lemon solution, or use Ruffoni Cleaner, a powerful metal shining powder that is both non-toxic and biodegradable. Then scrub vigorously with a soft cotton cloth for copper polishing, which is available in special stores.