Place the stained pot or pan on a stovetop burner.
Pour vinegar over the bottom of the pan or pot, making sure it covers the entire surface.
Pour an equal amount of water into the pan or pot.
Add 1 tablespoon of baking soda.
Place the cover on the pan and bring the mixture to a boil. Let the mixture boil for 20 minutes.
Scrape the stain with a wooden spoon or plastic spatula to see if it has loosened.
Remove the pot or pan from the burner and pour dirty liquid into the sink.
Cover the pan with baking soda and scrub with a mesh cloth or sponge until the entire stain is gone.
Rinse the pan thoroughly with fresh water.