Science Fun! Easy Penny Cleaning

By Jen Anderson and Michelle Schwab March 18, 2022
Did you know that you can clean your money? Make your dirty and dingy pennies bright and shiny with a little chemistry!

You will need:
  • 1/4 c vinegar in a non-metal bowl
  • 1 tsp salt
  • Old, dirty pennies
  • Bowl of water
  • Paper towels for drying
Set up your work space.

Mix the salt and vinegar. Add your dirty pennies to the salt and vinegar combination. Let them sit for about 20-30 seconds (longer if your pennies are super dirty).

Remove them from the vinegar and rinse them in the bowl water. Remove them from the water and dry them with a paper towel.

What's going on?

Pennies are made of copper. When copper is exposed to air over a period of time, the air reacts with the copper and forms a dull green crust called a copper oxide.  Vinegar is a type of acid.  The acid breaks the bond formed by the oxide and dissolves the copper oxide, exposing the shiny copper.