I have a grill pan with some cooking residue on it. I'm not exactly sure which food caused it (usually oven cook chips, pizza or grill sausages, burgers, sometimes mackerel) but something left this and I'm struggling to clean it.

It's very black, and also very smooth. It's been in the dishwasher, soaked in washing up liquid and also tried sodium percarbonate on it. I've tried scrubbing with both a sponge (rough green side) and some natural scrubbing thing we have. Nothing has touched the perfectly smooth finish and removed any of it.

The only way I've found is to scrape it off with a metal utensil. I successfully removed quite a lot (just the right amount of pressure makes it lift ok) with a wide palette knife. But this method is high risk when it comes to scratching the non stick coating off, so I'm looking for a safer alternative if anyone can help?

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    Does this answer your question? How to remove film from stainless steel pan
    – Mr Shane
    Commented Mar 8, 2022 at 15:55
  • @MrShane I guess it does now, but only after rumtschi identified what it was. I've seen orange build up like that other question elsewhere and been able to scrub it off. This seems a different colour and is much tougher so I'm not sure if it's a direct duplicate
    – Ian
    Commented Mar 8, 2022 at 18:29
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    @MrShane also I realised theres a difference - as having a non-stick coating means you can't just attack it like you could a stainless steel pan.
    – Ian
    Commented Mar 9, 2022 at 9:08

5 Answers 5


This is polymerized oil - the same stuff that people build up on iron pans as seasoning.

There is no good way to remove it from a coated surface. It is quite resistant to both chemical and physical methods, as you discovered. Most mechanical methods will scratch your existing coating, and as for chemical methods, the only reliable one is lye. If the existing "nonstick coating" is enamel or teflon, it shouldn't be damaged by the lye, but we cannot tell for sure from a picture.

You can also leave the spot there. The problem is purely cosmetic, it is perfectly well suited as coating for a pan (as said above, it is created on purpose on reactive surfaces).

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    @Ian note that the polymerized oil isn't something as a result of the pan material, it's due to the oil being exposed to high temperatures and oxygen. This may be the mechanism by which cast iron is seasoned, but it occurs independent of the actual surface material. Commented Mar 7, 2022 at 7:46
  • @fyrepenguin not totally independent - metal atoms and oxides works kinda as catalyst to speed up this process. That's why in older oil based paints there was often lead added. Linseed oil will polymerize faster on bare metal.
    – Mołot
    Commented Mar 8, 2022 at 11:52
  • @Mołot but once you lay down the first layer(s) of seasoning, doesn’t that become superfluous? Since the substrate is now polymerized oil instead of the metal. Commented Mar 8, 2022 at 18:02
  • @fyrepenguin can't tell for sure. Don't know if metal atoms migrate into first layer and can affect further layers. All I know first layer polymerization is in my experience faster and I can coat wok with pretty sturdy layer and still have no problems with cleaning oil drips from baking pan. I never allowed second layer to occur on the baking pan :)
    – Mołot
    Commented Mar 8, 2022 at 23:20

It might be polymerized oil, which is difficult to remove, but the way it’s smeared on the lower right, it might just be something sugary that dripped and has just caramelized onto the pan.

To see if that’s the case, place it somewhere that it can sit flat, and flood it was water. Leave it for a few hours (or overnight), and then use a plastic spatula or to scrape it gently. If it’s sugars, it should now be loose and come off fairly easily.

If it loosens, but doesn’t come off fully, then scrape off what you can, and leave it to soak some more.

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    And I don’t think it’s oil because it’s uniformly dark (except for where it looks like you scraped it). If oil seeps under the food, it usually ends up being orange-ish, rather than fully turning black. (Which is still a pain to clean off)
    – Joe
    Commented Mar 7, 2022 at 15:14
  • Appears as though this has already been tried, as I assume "soaked in washing up liquid" would include water. Commented Mar 7, 2022 at 16:17
  • @DarrelHoffman : yes, but for how long? It can take hours for it to soften up, depending on what the exact composition is. A short 15-20 minute soak won’t do it. And dishwashers don’t typically do it, either
    – Joe
    Commented Mar 7, 2022 at 16:59
  • @Joe sorry, I'm fairly certain I left this to soak overnight and it didn't help but I might check again!
    – Ian
    Commented Mar 8, 2022 at 11:26

It’s enamel coated re tray, and usually result of engaging self clean oven feature on newer ovens pyrolytic cleaning. Lye doesn’t work IME as these deposits are actually now bonded together. One cannot remove the one without laying waste to other.

You could Try jet/butane torch applied locally for as long as it takes to combust fully…

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    Note the torch approach should only be attempted if you're absolutely sure it's not Teflon (PTFE) coated. (The OP says there's a non-stick coating.) While Teflon is fine under regular cooking conditions, a direct flame hot enough and long enough to burn off polymerized oil will also burn off the Teflon, not only ruining the non stick coating but also exposing you to toxic gases in the process.
    – R.M.
    Commented Mar 7, 2022 at 14:56

You might be able to remove it with some strong (and by strong, I mean corrosive to skin, so wear gloves!) oven/grill cleaner such as HG Oven, Grill and Barbecue Cleaner. Best option is to spray it on, put it in the oven and heat it up a little, to about 50C/120F, that makes it work better. Leave for a while, then wipe off with a damp cloth.

Sometimes stuff like this can be removed with a less harsh approach, make a paste of sodium bicarbonate and water, and really go to town with the scrubbing, lots of pressure, perhaps use a nylon brush for a few minutes, you might see it slowly fade and break apart. But that might not work for the toughest residue.


Slice/scrape it off with a razor blade

There are utensils for this, getting one might be easier on the fingers. I do this with the most insisting stains, but do mind your fingers. If you insist on doing it with the blade alone, remember razor blades are flexible, but they do snap in the end. Dont bend it.

If it isn't completely hardened, soaking in vinegar might help, but mechanical cleaning is the best solution.

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