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.