The inner pot (cooking pot) of Instant Pot are made of food grade 304 (18/8) stainless steel. It is durable and can retain its appearance for years under proper maintenance.

Bluish or “rainbow” discoloration is common on stainless steel cookware including Instant Pot inner pot. This is caused by minerals or salts in the food and water. This discoloration is easily removed by using a non-abrasive stainless steel cleaner, which will help to retain the original brightness and assist with the removal of stubborn marks.

However, the easiest, quickest, and cheapest way to remove the rainbow stain from the inner pot is to cover the bottom of the pot with white vinegar. Let it sit 5 min, pour out, and rinse the pot. The discoloration marks can normally be removed completely. White hard water stains can be removed with a sponge dampened in vinegar or lemon.

The following pictures show our experiment with an Instant Pot inner pot under regular use for about 8 months.  We used Heinz’s Pure White Vinegar.

Bluish and rainbow marks at the bottom of inner pot.

Another picture of the bluish and rainbow marks at the bottom of the inner pot.

Inner pot after vinegar cleaning


Please  avoid using steel wool in cleaning, which will scratch the surface.

There is also more information cleaning and maintaining stainless steel cookware on the Internet.  For example, on eHow and British Stainless Steel Association.

12 replies
  1. Sherry Melancon
    Sherry Melancon says:

    I’ve had my IP less than a week and I have used it 3 times. I love it, but I have a dumb question, should the stainless pot have a slight bow in the bottom?

  2. paulette
    paulette says:

    Made Pork and sauerkraut, now have dark spots around middle of pot and on rim.
    Since this dish is a vinegar dish, I’m not sure what happen. Does anyone have any thoughts. Thanks for the feed back.

    • Kentuckylady717
      Kentuckylady717 says:

      Paulette read the top comments….they work, I don’t have the Instant Pot yet, but thinking about buying one, but I do have some stainless steel cookware and cleaning it with the vinegar and water or bar keepers’ friend works for me…..also with the no stick cookware, sometimes it gets a rough feeling in bottom, I pour water & vinegar in bottom to cover it and let it sit for awhile…..maybe 10-15 mins. never really timed it, but then just rinse it out and it feels real slick again….I don’t use bar keepers’ friend on those pans, just stainless steel….and I use a rough sponge like scrub daddy from QVC Lori from Shark Tank had them on…..:) they get soft in hot water, but stay hard in cold water….so best to scrub with them cold…..try them if you haven’t used them….better than just the plain sponges….

  3. Cathy B
    Cathy B says:

    How do you get burnt food completely off the inner pot? I got most of the food residue off heating a little white vinegar in there, and then lightly scrubbing with nylon sponge, hot water and detergent, but there is still some dark discoloration and a little residue left. Does anyone know any other ways to get it looking back to new, again, and not leaving food residue there to cook more food on?

    • Fred Miller
      Fred Miller says:

      So much work and still the results aren’t what they should be. An approved product for use in ALL commercial eateries and bars the the Country is Bar Keepers Friend, Cookware Cleaner and Polisher. It WON’T scratch your stainless, etc. Use a wet dish rag or sponge to remove food, clean and polish. Rinse well and dry or if you like, wash with hot water with a tad soap. You won’t find a 5 star restaurant in the Country that doesn’t keep this on hand at all times. Get it from Amazon.

      • Speedwell
        Speedwell says:

        We can’t get Bar Keepers Friend where I live (outside the US). I use the same method I use for cleaning my stainless steel kettle and other pans: a couple cups of water, a cup of distilled white (not malt) vinegar, a teaspoon of salt, and a brisk boil and sit… for the Instant Pot, that means two minutes of high pressure and a natural pressure release. No scrubbing needed at all.

  4. June Walker
    June Walker says:

    Such a simple and efficient tip! I just cleaned few of my stainless steel pots this way, and the result is great. I wouldn’t think of that by myself. Definitely recommending your post to my sister, she’ll be very glad to have your idea on mind. 🙂

  5. Ira Goldstein
    Ira Goldstein says:

    I’ve used Kleen King on our copper-bottom stainless steel Revereware for 35 years. I just did the “test run” an my new IP and it did leave residue (even with soft water.) I brief soak in vinegar did the trick. I might start doing that with my pans!

    I’ve also noticed that acid foods — tomatoes and such — leave the pans clean of residue.

  6. Fred A. Miller
    Fred A. Miller says:

    The easiest way to remove ANY stain on stainless and NOT damage nor scratch the metal, is to use “Bartenders Friend”. And, unlike Comet and some others, B.F. is safe around food.

  7. LauraD
    LauraD says:

    I used my Instant Pot the first day it arrived. I cooked a pot of mixed beans with vegetable broth and water. I got this typical “bean residue” on the inside of my beautiful stainless steel pot. Discouraged I checked websites to see how to get rid of the bean redidur. The standard was the white vinegar soak. I waited because I was out of vinegar. The next day I wanted to try cooking another dish to test my new Instant Pot. I dumped a 3# bag of frozen chicken tenders, herbs, olive oil and 1/2 cup of lemon juice. I set the Instant pot for poultry. It came out GREAT. AND, the stainless steel pot was like brand new again! Happy accident. So, cooking with an acidic juice does the same as soaking with the vinegar.


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