To clean copper, first determine whether it has a lacquer finish, then wash it accordingly. Lacquered copper can be washed with warm water and soap, and unlacquered copper can be polished with a salted lemon.
- Determine if the copper is lacquered or unlacquered
How you clean the copper depends on whether or not it has a lacquer finish. If the copper is shiny and glossy or if it gets dirty without changing color, it has a lacquer finish. If it has a gentle, subdued glow or it changes to a brownish color when grimy, it is unlacquered.
- Clean lacquered copper with soap and water
Make a solution of warm water and soap. Make sure it's not too hot or too cold. Gently wash the piece of copper with a non-abrasive cloth, and dry it with a soft, absorbent cloth.
- Clean unlacquered copper with lemon and salt
Slice a whole lemon in half. Dip the lemon half into Kosher salt for plain copper pieces, such as cookware. Use table salt for pieces with engravings, or fragile items. Gently use the salted lemon to scrub the copper in circular motions until it's clean. Rinse the piece with warm water, and dry with a soft towel.