Baking Soda and Lemon Juice

• Baking soda and lemon juice are both safe and natural cleaning agents. When you combine the two ingredients, you get the collective benefits of citric acid and sodium bicarbonate, useful for removing tarnish and restoring copper's natural shine. Mix the baking soda and lemon juice into a thick paste and apply to your copper surface using a toothbrush. For a fine paste, you should need about 1/4 cup of lemon juice and 3/4 cup of baking soda. After working the solution into the copper, wait 15 minutes to an hour before rinsing and drying.
  
  

Vinegar and Salt

• Vinegar and salt works similarly to baking soda and lemon juice, but using a slightly different acid and chemical compound--acetic acid and sodium chloride. Like baking soda and lemon juice, these ingredients are all natural but in order to make them into a paste, you will need to add about 3 cups of white flour to 1 cup of vinegar and 1 tbsp. of salt. Apply the solution exactly as you would apply baking soda and lemon juice.
  
  

Grape Seed Oil

• Grape seed oil is derived naturally from grapes and boasts a myriad of benefits, from skin moisturizing to cholesterol reduction. In addition, you can use grape seed oil to clean copper surfaces. While this method may not work for large surfaces like pots and pans, it can work wonders for small objects like copper coins. Just fill a cup with grape seed oil and place your copper items inside overnight. The next morning, scrub each copper item with a toothbrush, rinse and buff dry.
  
  

Ketchup

• Ketchup contains vinegar and salt, two of the aforementioned ingredients useful for cleaning copper. In addition, the tomatoes contain citric acid and malic acid, which further assist in the cleaning process. Just buff copper surfaces with ketchup, wait 15 minutes and then wash the ketchup away. Buff dry with a a non-abrasive cloth.