How do you clean copper?
Copper is valued for strength, malleability, ductility, and ability to conduct electricity and heat. It is also non-magnetic, resists wear, and forms a green patina which makes it resistant to corrosion. Copper is used to coat bottoms of steel pans to improve heat conduction, for decorative items, and in a few other cookware applications. It is also used for electrical wiring, plumbing pipes, and many uses in appliances. Decorative items should be kept clean and dusted. Copper is sensitive to air, and oxidizes (tarnishes) faster in moist air. Coating with lacquer, if not being used for food purposes, helps preserve the finish.
Most pieces of decorative, modern copper are protected by a factory-applied, baked-on lacquer. Only dusting and an occasional washing with lukewarm, soapy water are needed to keep lacquered objects shiny. Never polish them. Lacquer must be removed from eating and cooking utensils before using. To remove lacquer, place the item in 2 gallons of boiling water to which 1 cup of washing soda has been added. The lacquer will peel off. An alternate method to remove lacquer is to rub with a cloth saturated with acetone or alcohol.
Copper Pots: To remove tarnish from copper pots, rub with lemon halves dipped in salt.
Copper Utensils with copper interiors should never be used for acidic foods, with pH of 6.0 or below, since toxic compounds can form if food is cooked, stored or served from such containers. Even if copper pans are lined with tin, they should not be used for acidic foods such as fruits, fruit juices, salad dressings, tomatoes, vinegar containing foods, etc. Copper bowls may be used for beating egg whites, or copper kettles for cooking high sugar foods like fudge, for these foods are alkaline. Utensils with copper on the bottom or outside, and stainless steel, aluminum, or a porcelain enamel interior finish are safe to use and conduct heat well. Avoid high heat which discolors copper bottoms. Ideally you should clean copper bottoms after each use, even though the tarnish does not affect cooking results or the pan's efficiency. Do not use an abrasive cleaner or steel wool to clean copper bottoms. Wash tarnished copper utensils with soap and warm water and polish with a cleaner of equal parts of salt, vinegar and flour. After rubbing the item with this mixture or any polish, wash it carefully, rinse thoroughly and dry.
Vinegar and Salt. If copper is tarnished, boil article in a pot of water with 1 tablespoon salt and 1 cup white vinegar for several hours. Wash with soap in hot water. Rinse and dry.
Salt, Vinegar, and Flour. Dissolve 1 teaspoon salt in 1 cup white vinegar. Add enough flour to make a paste. Apply the paste to copper and let sit for 15 minutes to 1 hour. Rinse with clean warm water, and polish dry.
Lemon and Salt or Baking Soda. Make a paste of lemon juice and salt, and rub with a soft cloth, rinse with water, and dry. Or use a slice of lemon sprinkled with baking soda. Rub copper with the lemon slice and rinse with water and dry. Vinegar and Salt. Pour vinegar over the surface Sprinkle salt over the acid and rub in the mixture. Rinse with warm water and polish dry.
Lemon Juice and Cream of Tartar. Make a paste of lemon juice and cream of tartar. Apply, leave on for 5 minutes, and then wash in warm water. Dry with a soft cloth.
Tarnished Copper: Polish with a commercial polish for copper following directions on the container. Polish can be made at home by moistening salt with vinegar or lemon juice to make a paste for a bright finish or a paste of rotten-stone and olive oil for a dull finish. After polishing decorative items, spray with lacquer to preserve color if desired.
"Bronze Disease" also attacks copper. Use hot vinegar and salt, or lemon juice and salt, copper cleaner, or buttermilk to remove these patches of corrosion. After treating, wash promptly with soap and water, rinse and dry.