Unsightly burn stains on a stainless steel pan are the result of walking away from the stove and forgetting about food that's cooking or simply using too much heat while cooking. In either case, the food will burn and mar the pan. If you do not treat a burnt pan promptly, the stains will set further as you continue to use the pan, and will affect the flavour of any food cooked in it. Clean a stained pan as soon as possible with supplies that are gentle yet effective for safely cleaning stainless steel surfaces.
Pour vinegar into the burnt pan until the burn stain is covered.
Place the pan on the hob and bring the vinegar to a boil. Boil it for five minutes then remove the pan from the stove and allow it to cool to the point where you can handle it.
Set the pan in the kitchen sink with the vinegar still inside. Scrub the burn stain with a nylon dish scrubber. Sprinkle in a bit of baking soda to add mild abrasiveness that won't scratch the pan's surface.
Treat any remaining stains by filling the pan with hot water and adding a few drops of dish washing liquid.
Allow the pan to soak for an hour, to help loosen any lingering burn marks.
Scrub the inside of the pan with the dish scrubber. Rinse the pan thoroughly with water to remove the dish soap and any burn-stain bits.
Dry the pan with a lint-free kitchen towel.
Place the pan in the freezer for a few hours to make it easier to remove any burn stains. Rather than boiling the vinegar, you can soak the pan in undiluted vinegar to help remove stains. You can also use a fabric softener soak to loosen burnt-on food and grease stains.