Things You'll Need
If the copper surface is textured and the stain is stubborn, you can add a bit of salt and make the mixture more of a paste before rubbing it in for an abrasive effect. Do not use any salt if you need a smooth, unmarked surface.
Tea and other drinks are often set on tables without protection. When this occurs, the wet residue from the sweating of the vessel used can leave a white mark on the surface. If the table is made of copper, it needs particular care to remove that stain.
Put 3 to 4 drops of dish soap in a small cup-sized container.
Fill the container with warm water.
Add 4 to 5 drops of white vinegar to the mixture.
Stir mixture well to make it foamy.
Dip sponge in mixture and squeeze until just damp.
Wipe water stain with the damp sponge until it is gone.
Dry the surface with a soft cloth.