Diatomaceous earth can be used as an abrasive for cleaning and polishing. The silica which makes up DE is an extremely porous and fine powder, yet very hard. This makes it ideal for copper on pots and pans, which is often susceptible to discoloration and stains from prolonged use and exposure to hot grease and other oils.
Follow the steps below to polish and remove stains from copper cookware with DE.
Make a polishing paste by adding a few drops of vegetable oil or milk to a tablespoon or two of DE. The DE should begin to dampen slightly.
Dampen a cloth with vinegar and dip it into the DE mixture.
Rub the copper surface with the cloth and DE in a circular motion. Apply varying pressure as needed. Repeat until the copper is cleared of grime and stains and shows a noticeable increase in shine.
Rinse the copper cookware and dry immediately.
Do not use this technique on areas of pots and pans with nonstick coating.