Sort the pennies and keep only copper ones
Wash the pennies with warm water and mild dish soap
Rinse the pennies thoroughly
Dry the pennies with a soft cloth
Soak the pennies in white vinegar for a few minutes
Sprinkle salt on the pennies or mix salt into the vinegar
Gently rub each penny with a soft cloth or cotton swab
Rinse the pennies again with clean water
Dry the pennies completely
Use a baking soda paste for stubborn tarnish
Rub gently and avoid scratching the surface
Stop cleaning if the penny is valuable or collectible
Store the cleaned pennies in a dry container