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Iridescent Effect on Cooktop

Iridescent, silvery, or rainbow effect on cooktop glass-ceramic

Sometimes odd looking stains show up on a glass-ceramic cooktop.  What are the iridescent, silvery, or rainbow looking marks on the burner area?  Some people claim these are “inside the glass” and have come for no apparent reason.  There is a reason.  And that reason is using the wrong cleaners to clean a surface that reaches 1200℉.

Dish soap was not designed for 1200℉ on dark black glossy surfaces!  When you clean with dish soap, or any detergent, some of that cleaner remains on the surface after wiping it off. 

This past week I was contacted by a consumer from the lovely state of California.  She provided a picture similar to the thumbnail photo in this post and stated her relatively new cooktop had a silvery, rainbow looking mark inside the glass burner area  and it was getting worse over time.  She also stated that she kept the cooktop very clean and only used a mild dish soap with water to clean, and no significant food spills during cooking yet.  Was her cooktop defective?

The key comment she made was “dish soap.”  Yes mild-mannered dish soap, which is readily available and good at removing grease residue from most any surface, may be the culprit here.  Dish soap was not designed for 1200℉ on dark black glossy surfaces!  When you clean with dish soap, or any detergent, some of that cleaner remains on the surface after wiping it off.  Unless you thoroughly rinse the surface, some dish soap is still on the surface and will get quite “baked” once you turn on the heat!  I sent her a sample of a good cooktop cleaner, like shown in my cleaning method post and asked her to try cleaning with this cleaner instead, then get back to me.  After a day, she responded with a note of success, the rainbow is no more.

With that in mind, I recreated this dish soap mark after 5 or so cycles of boiling water using my test apparatus and some spare CERAN® glass-ceramic.  It didn’t take too long.  Here’s how I did it:

  1. Sponge cleaning with dish soap on glass-ceramic cooktopEach time I wiped the cooking surface with a sponge soaked in dish soap and water.
  2. Wiping cleaned surface dry after using dish soap on cooktop glassNext, I lightly wiped the surface dry with a paper towel.  As with the consumer who contacted me, on occasion the surface was still mildly warm, not hot, and the soap dried on the surface lightly.
  3. Cooking after cleaning with dish soapThen, I boiled some water on the recently cleaned surface and let it cool.
  4. Silvery stain shows up after one cleaning and heating after dish soap on cooktopEven after the first cycle, a small rainbow ring begins to form under the pan.  The open hot surface does not show this surface mark, only the region under the pan.  Keep this in mind as it’s possible the soap residue on the bottom of the pan can also cause this mark to show up. 
  5. Recreated Iridescent rainbow stain on a glass-ceramic cooktopAfter several cycles of wiping with soapy water, wiping, and boiling water, the residue has grown.  Note, the pans I used had wavy lines on the bottom surface and those lines are mirrored in the marks on the surface.
  6. Cleaning silvery iridescent stain from a cooktopThe good news, these marks can be prevented using the correct cleaner.  Even better news, a good cooktop cleaner like Weiman or CeramaBryte takes this rainbow off very easily!  Here I divided off a small section of the stain with tape, and cleaned it with CeramaBryte.  See post on best how to for cleaning.
  7. Iridescent Effect partially cleaned from cooktopThe final result, the sectioned area cleaned quite well.  I used some “elbow grease” when wiping with the cleaner.  It certainly did not just wipe off with no effort, but with some repeated effort, cleaned off fine.  Note some the surface effects still visible are only a reflection of the window and sky in the glossy black surface.

If you have something you would like us to test or explain, let me know.

Happy cleaning…

Ted

 

 

 

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22 Responses to “Iridescent, silvery, or rainbow effect on cooktop glass-ceramic”

  1. Arwa July 16, 2015 at 12:49 am #

    This was very useful thanks!

  2. Peter July 17, 2015 at 3:09 am #

    I have a new glass top stove, only about 3 weeks. Tonight we cooked veggie burgers in a frying pan and when I removed it from the stove top, there was an iridescent stain that looked like it was beneath the glass. Needless to say I was not happy. After searching online for solutions on how to get rid of it, I came across a post that said to use “Bar Keepers Friend” which I already use for my pots and pans. I squeezed some out onto a damp dish rag and then rubbed onto the stain. IT WORKED INSTANTLY! Try it. I’m so relieved.

    • Ted Wegert July 18, 2015 at 11:20 am #

      Thanks for the comment Peter. One note of caution with Bar Keepers, at least the traditional formula. BK is not designed for glass-ceramic. So, yes I have found it to be very fast on tough stains, BUT I would not recommend it. To my knowledge the abrasive contained is not controlled for application on glass-ceramic and it could scratch since the hardness of abrasives used at times may be harder than the glass-ceramic. That means, the spot may be off but a dull or slightly scratched surface will be left, especially with long term use. For those users with little to know decoration on their cooktop design and an all black high gloss surface, they may have a real problem. There are many cleaners out there. If you think in terms of a brand new expensive black automobile, you have lots of choices on cleaners in your kitchen…but not all safe to use. It really is a good cleaner to get the gunk off the pans, just be sure to rinse them afterward.

  3. cynlis October 14, 2015 at 3:44 am #

    i have stopped using the dish soap on my cook top and now only have used weiman glass cook top cleaner and a ton of elbow grease, yes i still have a rainbow and a few other marks. https://www.dropbox.com/s/y5hxfszsn4ro9mz/2015-10-12%2020.36.45.jpg?dl=0

    • Ted Wegert November 13, 2015 at 9:45 pm #

      Interesting picture. This is not really the rainbow I was creating with the soap, but it might be related. Keep working with the cooktop cleaner and razor scraper. Maybe try a mix of baking soda and water rubbed in a circular polishing motion to try to remove that. I’d love to recreate this mark to get more experience with it…but not sure on this one.
      Ted

  4. Angie Lucas January 13, 2016 at 2:45 pm #

    Awesome results! I would definitely try this cleaning way. You got a perfectly clean glass-ceramic cooktop. Greetings

  5. Toddy Turrentine September 9, 2016 at 6:24 pm #

    Hi Ted: I am in a panic about the iridescent stains on one burner of my induction cooktop. There is no baked on residue or raised deposit; it does look like it is underneath the glass. KitchenAid is going to look at it, but I’m worried they will reject any claim because they will think I used the wrong cleaner. My dish soap has not ammonia, and I don’t think I ever used it. My Glass Plus is ammonia-free, but I worry my occasional cleaning person refilled the bottle from a big bottle of regular Windex in the basement. Can I get these off? How can I send you pictures? Thanks so much

    • Ted Wegert September 9, 2016 at 7:50 pm #

      No worries…just go get some Weiman Cooktop Cleaner or Cerama Bryte Cleaner and scrub it off! It comes off with the correct cleaner.

  6. Toddy Turrentine September 9, 2016 at 8:40 pm #

    Amazing. I got the CeraBryte, rubbed really hard, and the stains came off. Thanks so, so much for your information. I thought I would need a new cooktop!

    • Ted Wegert September 10, 2016 at 12:55 pm #

      Awesome. Thanks for the feedback!

  7. Mark December 18, 2016 at 11:13 pm #

    So, I have an (old) Ceran-brand top that is brown-ish with tiny tan (?) polka-dots all over it (by design, not stains) making for a “pebbly” surface. For this reason, I did not try the razor blade method.

    For the black rings (burned food stains?) around the burners, a lot of elbow grease and baking soda paste took 80% of it off. Soaking the remaining stubborn black residue with oven cleaner got the rest of it up, and seems to do no harm to the top.

    However, the silvery/rainbow/iridescent stains in the middle of the burner persist. These seem to be in the shape of the bottom of pots, so it may be metal transferred from a previous owner’s cookware? So I bought Ceramabryte – no change. I tried Barkeeper’s friend – no change. I soaked the stains in distilled white vinegar 10 minutes – no change. Got out my Porter-Cable buffer and tried Meguiar’s fine cut cleaner – no change.

    The stovetop is probably 10 years old and all this damage was there when I got it. But nothing I’ve tried thus far will touch the silver/rainbow-y stains.

  8. Lucy January 11, 2017 at 12:35 am #

    I have fine white specks on my ceramic top, only 2 months old. From reading the above I’m thinking that I’ve not cleaned off my hob brite enough. Is it worth me giving CeraBryte a go?

    • Ted Wegert January 17, 2017 at 1:22 am #

      Yes, correct cleaners REALLY DO HELP. Weiman or CeramaBryte. T

  9. Clayton February 13, 2017 at 5:26 pm #

    Nice web page. Just got done arguing with Whirlpool Kitchenaide that I have a “silvery discoloration under the glass surface” of one of my cooking eyes. It didn’t look like your pictures but I’m going to try the cleaners you mentioned. Any preference Weiman over CeramaBryte?

    • Ted Wegert February 19, 2017 at 6:31 pm #

      Both should work. Sometimes baking soda and water has some good abrasive qualities but the cleaners have other properties which help.

  10. Clayton February 14, 2017 at 3:27 pm #

    Update: I used Weiman Heavy Duty. Worked like a charm. I am the hero of my house (for today). 🙂

    • Ted Wegert February 19, 2017 at 6:24 pm #

      Well done! Small victories, one day at a time!

  11. Ola March 25, 2017 at 10:18 pm #

    Hi
    My cermaic burner has real colored rainbow and also looks that it is burned or damaged
    I tried a couple of times the crema bryte but it didn’t help
    Any advice?

    • Ted Wegert May 4, 2017 at 6:36 pm #

      Try Weiman and some high pressure on the paper towel with cleaner on it.

  12. Joanna McGuire March 31, 2017 at 1:29 am #

    The very first time my husband used our brand new ceramic glass top range, low and behold, what appeared to be bubbles of iridescent chips under the glass were left where the pan he used was rested. Both of us stared at it in disbelief, inspecting the “crime scene” with heads tilted in every conceivable direction. After duking it out with the dishwasher installer who managed to crack an existing pipe under the sink coupled with our HVAC and stove going kaput my nerves had lost their typical rattle. After subjecting my poor husband to rapid-fire questioning, I simply shrugged it off while he stood speechless. I confess criying tears of frustration for a minute or two in the bathroom. Then along came Ted Wegert’s blog echoing in perfect harmony with our conundrum and putting to an end the undeniably gnawing feeling that we had a defective range on our hands. Using a RAZOR BLADE on a new cooktop?! Couldn’t be. But Ted wrote with authority sprinkled with a generous dose of compassion and won me over. Over two weeks passed from that same day we dashed to the store and purchased a CeramaBryte kit. When we got to the store my mind went blank and my tongue locked: I managed to get out the words “ceramic glass top” coupled with a look on my face that would probably scare even me. The woman who watched me frantically scan through the product line-up and heard me sigh out an expletive starting (understandably) laughing followed by “I know exactly what you’re looking for.” There it was: the jewel of confounding cooktops. I then wound up watching how-to videos which chased the courage right out of me, and after reading and rereading Ted’s blog, in soldier-like fashion sucked in my belly and headed to the range with blade in an awkward hand. The cooktop now looks better than on delivery day, and we are indebted to you, Ted. Thank you falls short; we are so deeply appreciative for your work. And, yes: thank you so very much!!

    • Ted Wegert May 4, 2017 at 6:33 pm #

      Nice story! Thanks.
      Ted

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