How to Clean Old Pennies

If you have a jar of corroded, old pennies, don't leave them sitting around the garage. Instead use your old pennies to try an enjoyable science experiment with your kids. Acidic liquids, rather than basic liquids, will clean a penny, according to the Miami Museum of Science official website. By making pennies shiny and clean, you and your child can discover which household materials are acidic and will give old, dirty pennies a clean, nearly new appearance.

Things You'll Need

  • Ketchup

  • Toothbrush

  • Vinegar

  • Bowl

  • Lemon juice

  • Salt

  • Cola

Step 1

Apply a small amount of ketchup to an old toothbrush and carefully rub both sides of the penny until it shines, recommends the website Rinse the penny with water to remove the ketchup.

Step 2

Drop an old penny in a container of vinegar and let it sit for a few minutes until the penny is completely clean. The acid from the vinegar will clean the penny and make it shiny.

Step 3

Place old pennies in a shallow bowl of fresh-squeezed lemon juice, then add a few pinches of salt. Leave the penny in until it is clean. Leaving the penny in the mixture for too long, however, may make the penny turn black.

Step 4

Pour a small amount of cola into a bowl, then drop an old penny into the liquid. Leave the penny in the cola for several minutes, then remove the sparkling clean penny.


Like ketchup, any sauce that contains vinegar will clean a penny, including steak sauce or hot sauce.


Supervise young children while they perform penny-cleaning experiments.

References & Resources