What You Need to Know About the Discoloration of Stainless Steel Due to Heat

Updated: Jul. 23, 2023

While it won't have any effect on your food, it can be unsightly and bothersome.

Our pots and pans mean a lot to us. I mean, how could they not when we spend so much time with them in the kitchen? We always hope they’ll stay sparkly and shiny like new forever, but that’s usually not possible. That doesn’t mean we haven’t tried, though—cleaning the black bottom of a pot and the burnt bottom of a pan are hacks we’ve happily tested.

But what about that odd discoloration of stainless steel due to heat? Fortunately, that weird rainbow film on your cookware is easy to fix.

What’s with the Rainbow Stains on Stainless Steel Pots?

If you’ve ever come across this odd, colorful film on your stainless steel pots, you’re not alone. It’s all down to science! Stainless steel pots often contain chromium, a sturdy metal, which helps keep them from rusting or corroding. Mix oxygen and chromium, and you’ve got yourself a little rainbow show all to yourself. It’s basically a thin protective layer that changes color when combined with air and high heat. But don’t worry…it’s completely safe.

Here’s how to pick a safe nonstick pan.

How to Get the Stains Out

Yes, your pots are totally safe with the rainbow residue. However, it may still be a bit too unsightly for your clean kitchen taste. That’s OK—we’ve got the solution. As you may already know (’cause we know you know), the answer is…vinegar! We use vinegar to clean basically everything.

Take some diluted white vinegar and scrub with a non-abrasive sponge. Then after thoroughly working the vinegar into your cookware, you just need to rinse and dry. The acidity of the vinegar will work to break down the oxidized rainbow layer to keep your stainless steel pots looking their silvery best.

Tools You’ll Need

Next: Learn how to clean all your pots and pans, from stainless steel to nonstick and copper.