Check any labels or instructions that accompanied your enameled copper for warnings before proceeding and follow them judiciously.
Wash the item with warm, but not hot, water and dry it thoroughly with a clean, lint-free cloth. Do not use an abrasive scrubber.
Mix a cleaning solution from one of the following, based on the degree of dirt or tarnish on your copper: for mild, mix equal parts of vinegar, salt and enough flour to make a thick paste; for medium to severe, mix two parts lemon juice to one part baking soda. If you don’t have flour, you may substitute cornstarch or corn meal for the mild concoction.
Apply a small amount of the cleaning solution of choice to the dirty or tarnished area with the soft cloth. Let the concoction sit for 30 minutes.
Rinse the item with warm, but not hot, water.
Sprinkle the item with baking soda, lightly rub it in with a paper towel and then rinse. Dry the item and then buff it thoroughly to a bright shine.