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On March 3 2021, I bought this Zwilling 33 cm / 13 inch Aluminium deep saute pan with lid. Please review pictures below, inside my red circle. The coating on the surface appears to have corroded! Why? What went wrong?

I was careful not to scratch or corrode the coating! I used sponges to clean. I used plastic heat resistant Turners.

pan with damage in the center

pan with damage in the center

Anastasia Zendaya
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arab
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    Welcome to SA! I moved the photos into the post for you. – FuzzyChef Apr 16 '21 at 05:24
  • What's your habit for getting the pan up to temperature? If you see bob1's answer below, and the comments underneath, we think it might be getting too hot, so knowing how you heat it up would be helpful – Chris H Apr 16 '21 at 13:02

1 Answers1

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This is not corrosion, this is damage to the non-stick surface.

Overheating the pan can damage non-stick coatings. As these marks are in the centre of the pan I suspect that there are two possibilities:

  1. The pan was heated too hot and damaged the coating
  2. The "corrosion" is actually damage to a layer of polymerized oils/fats analogous to seasoning on a cast-iron pan.
bob1
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    From the photos, I'd think it's 1, not 2. – FuzzyChef Apr 16 '21 at 05:22
  • @koss 1 - yes, you can overheat, especially with non-stick pans. Plain metal can warp with overheating. 2. not generally, it might be possible to smooth it off with a light scour, but it will still be less non-stick. 3. It can be still used, but the more it is used, the more that surface will continue to degrade. I can't make any assertions on safety, but teflon (assuming its teflon) is quite inert, though I'm not sure that anyone has looked at the safety of ingesting these sorts of coatings. – bob1 Apr 16 '21 at 09:20
  • @bob1 There's a [paper on giving PTFE (teflon) as a *food supplement*](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4928218/) to fill the stomach with something inert/calorie-free. It doesn't sound like a good idea to me - microplastic pollution anyone? – Chris H Apr 16 '21 at 12:57
  • @koss it's easier on gas, with fairly thin-based pans, heated empty, as the heat source tends to be in points. Minimum heat should be fine for a few minutes, but preheating a non-stick pan hot before adding oil can do this. I tend to turn on a minimum flame, then get the oil, add it, and turn up the heat. That's habit from my enamelled pans that take ages to warm up and should be heated gently. – Chris H Apr 16 '21 at 12:59
  • PTFE is harmless for ingesting, this has come up in other questions. However, the binder used to attach the PTFE onto the aluminum pan might not be. – FuzzyChef Apr 16 '21 at 23:27
  • The linked page for the pan says "Non-stick Duraslide® Granite coating" and "PTFE Free" - now, that of course doesn't tell us what is **is**, but it does tell us what it **isn't**. Another reference quotes, "(the "granite" refers to its durability, not its composition). It's also free of PFOA, or perfluorooctanoic acid, a manmade chemical that is used to create some nonstick surfaces and Teflon; is safe to use with metal cooking utensils; and won't release any harmful fumes. " tbh, I'd ask Zwilling about it, as they're not letting on what it's made of or what temps it can stand. – Tetsujin Apr 17 '21 at 07:06
  • most non-PTFE based coatings are silica/silicon based ceramics. they do in fact put flakes of granite into these types of coatings - I'm not sure what functional purpose it serves – CobaltHex Apr 19 '21 at 07:55
  • also, I believe teflon (PTFE) coatings are applied after the aluminum/metal has been either sandblasted or caustic washed (e.g. with lye) to help the PTFE adhere. it's usually applied in several layers – CobaltHex Apr 19 '21 at 07:59
  • @Tetsujin I actually think that the "granite" does refer to the composition. The non-PTFE nonstick coatings are ceramic, and one can make ceramic out of pretty much any rock (or mixture of rocks). Now, it is unclear whether granite is the main component in the ceramic or added in homeopathic doses, and probably rather irrelevant too, because in my experience, all these proprietary ceramics work pretty similarly. The picture doesn't look like damaged ceramic though, much more like damaged teflon, which confuses me. – rumtscho Apr 19 '21 at 12:06