How to Clean Copper With Lemon, Vinegar or Ketchup

Cleaning and polishing an old copper mug with steel wool — Exposure to heat, air and humidity can very quickly change the appearance of copper. LS92 / Shutterstock

Copper is a useful and eye-catching material, but like many surfaces, it needs care if it's going to look and function at its best. Here, we explain how to clean copper and look at how the methods differ, based on what copper object is being cleaned.

Cleaning Copper Cookware

Here are some different ways to clean copper cookware. None of these is necessarily better than any other; the best choice for you will likely depend on what you already have in your kitchen.

If you have copper pots, copper bottom pans or other copper vessels in your kitchen, this method will be helpful for keeping them looking good and clean.

Method A: Scrub With Lemon

Sprinkle salt on half a lemon. Rub the salted side of the lemon on the tarnished area. The salt will act as an abrasive and the lemon will act as the cleanser. The combination will clean the tarnished area of the copper pan.

Method B: Use a Cloth With Lemon Juice

Squeeze a lemon and add some salt to the juice. Pour the mixture onto a cloth. Rub the mixture on the pot. Again, the combination of salt and lemon juice will clean the area.

Method C: Soak in Vinegar

Make a mixture of water and white vinegar in equal proportions. Then, add a tablespoon of salt. Use a soft cloth, like a microfiber cloth, to soak in some of the mixture and then gently rub it into the copper surface. If the tarnish is a bit heavy, wait just a few minutes before rubbing.

Cleaning Copper Coins

Use this method for cleaning copper coins such as pennies.

Make a paste of salt and white vinegar.
Rub the paste on the coins with a tooth brush. Let the paste sit for a while. If the coins are very tarnished, leave the paste on overnight.
Wash the paste off the coins, and they'll look like new [source: Martha Stewart].

How to Polish Copper

With enough elbow grease, any of the methods listed above will yield a nicely polished copper pieces. However, for an extra level of polish and shine — or if your copper has been badly tarnished — you can purchase a specially formulated cleaner that will have your copper cookware gleaming like new.

If you're using something like Wright's Copper Cream, make sure you've already washed your copper item (a regular dish soap will work well). Then apply a light coat of the cream, wearing gloves to protect your hands from anything corrosive).
Use a soft sponge, wash cloth or soft-bristled brush to cover the surface of the copper entirely with the cream.
Once the copper cleaner has been thoroughly applied to the copper piece, wash it with soap and water. Make sure it's thoroughly rinsed, and then dry with a soft cloth to eliminate water spots.

4 Other Methods That Work Surprisingly Well

There are plenty of ways to keep your copper pieces clean and shiny, and some might be a bit unconventional. Again, your success will depend on how much effort you want to commit, as well as what's in your kitchen.

When using a new method, apply a little bit to an inconspicuous area. This will give you a sense of how well it works (or doesn't), and then you can decide if you want to use the method for the whole copper item.

Ketchup: Believe it or not, ketchup works! You can use it if you don't have any lemons or lemon juice immediately at hand. Some methods recommend adding a little salt. Apply a layer of plain ketchup, let it sit for several minutes, and then wipe it off.
Bar Keepers Friend: Some recommend this consumer-grade kitchen cleaner as a way to use less elbow grease, although others have said it doesn't work as well as salt and vinegar. If you have some beneath the sink, it might be worth a try.
Salt and flour: You can also make a paste by adding equal parts salt and flour to a small bowl. Slowly add your acid of choice (white vinegar or lemon juice) until a paste forms, then apply it to the copper items you want to clean.
Baking soda and vinegar: This method isn't as popular as some of the others, with some users claiming it's just not as effective as acid and salt. The chemical reaction between acid and vinegar makes a foamy, vivid effect, but it might not be abrasive enough for a thorough clean or polish.

Why Do Copper Surfaces Change?

Most people are proudly display their copper cookware by hanging it on hooks in the kitchen. But that pride can quickly fade as the pots start changing color. Exposure to heat, air and humidity can very quickly change the appearance of copper.

This process is called oxidation, and it happens when the copper combines with the oxygen and moisture in the air and loses some of its protons. This causes the color of the metal to change to a deeper orange. Oxidation can also cause copper to develop purple and blue streaks.

If you leave it unchecked for a long period of time, oxidation will result in blue-green "salts" growing on you copper cookware [sources: American Chemical Society, Britannica].

Cleaning copper like a professional is easy and doesn't require complicated techniques and expensive chemicals; as you see, everyday kitchen items like white vinegar can act as a natural solution when you need to clean copper cookware and copper coins.

Maintaining Copper

It's important to remember that copper will develop a natural patina simply by being exposed to the air, and that this can actually help preserve the surface of the copper. Regular cleaning with soap and water will help keep the copper looking good.

If you do want to restore your copper to its original luster, use one of the aforementioned polishing methods, especially the specially designed cleaner. Since a complete polish is going to be time-consuming, it's always good to keep a maintenance routine, which will mean a thorough polish is less necessary.

After cleaning your copper pieces, rub them with a bit of mineral oil. This will help create a barrier between the copper surface and the air, which will cut down on the amount of tarnish that starts to develop.