So today I went to a flea market and found a copper pan with a stainless steel lining. I cleaned it thoroughly and the first thing I wanted to try is to caramellize sugar (because of the lack of fryable vegetables and meat in my fridge). While heating the empty pan it made some scary knocking noises as if I would take a spoon and tap the pan. Furthermore I saw steam escaping from somewhere at the pan. I thought this steam comes from the handle or somewhere else where I didn't dry the pan thoroughly enough.

Later on I searched for English, German, and Italian reviews and found a one and only bad review in German of a similar pan on Amazon. It basically says that water can be trapped between the copper and the steel and thus causes bulges and in the worst case an explosion. This review doesn't mention any noises.

Is the ingress of moisture between the copper layer and steel layer a thing? Was this pan a bad bargain? And how can I distinguish bad pans from good pans except by looking for reviews in the internet? Are there characteristics that I can look for (e.g. how the edge looks like where the copper layer and steel layer end)?

  • 3
    I had a similar issue but with a totally different type of pan. It was a commercial grade non-stick pan. I had the knocking noise when the pan was heating but I did not have the steam escaping from anywhere. It was quite disconcerting but I continued to use the pan and after a few weeks of use the "knocking" no longer happened. I'm still using the pan and it's been well over a year since I heard the noise. I still have no idea what caused it.
    – Cindy
    Commented Jun 28, 2015 at 20:15
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    Metal Deathwatch beetles? en.wikipedia.org/wiki/Deathwatch_beetle "these woodborers create a tapping or ticking sound that can be heard in the rafters of old buildings on quiet summer nights" Commented Jun 28, 2015 at 23:22
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    I don't know what the cause of the noises is. However, I would note that separation of the bimetal laminate in stainless/copper pans from the top producers (Mauviel, Bourgeat, Falk, etc.) is exceedingly rare. For lesser brands, I suppose it might happen. (Just to note the rarity: I've only ever heard of it from tinned copper fans. Not saying it can't happen, which it definitely could, but I've never actually seen a first-hand account on various cooking forums I've read on copper.) Anyhow, if separation was happening, you'd likely see significant warping, discoloration, or other pan damage.
    – Athanasius
    Commented Jun 30, 2015 at 2:06

3 Answers 3


I've had this issue also with new pans. I've purchased pans before that need to be seasons and tempered by heating in the oven. As any metal heats it expands, during expansion you will hear little knocks and creaks. I've had pans with rolled edges that trapped water from washing, has caused the water to escape as steam and whistle on its way out, very disconcerting sound.

You may try checking the manufactures website (check bottom of pan for name) to see if you may need to temper your new pan in the oven prior to using. My daughter and I are a stickler for reading directions on every new item we get, which is how I learned to temper my pans. I wouldn't worry too much about the sounds it makes, over time it will stop.

If the pan is a frying pan the easiest way to temper it is to put some oil in the pan and heat it till the oil comes to a smoking point (remember different oils have different flash points, cheap vegetable oil being one of the lowest). Remove pan from the heat and allow to cool, pour or wipe out any excess oil. For long lasting non-stick surface on your stainless steel pan don't allow it to come in contact with water. The stainless steel is very porous and the water will wash the oil away. Also, never put a hot pan in water, it will warp it. Watch the video I linked below to learn how to season your new pan.



I believe the ticking from my frying pan comes from where the handle is riveted to the pan. As the pan heats up and expands, it 'slips' under the rivets as the handle heats up more slowly. The reverse process happens as the pan cools.


I probably should say that the knocking noise is usually a common thing for low grade pans.Even sometimes they change shape while heating, mainly due to the misalignment of two components. It is not specific to copper or any other material but in any pans where two materials are mixed. While heating, usually the air in between the materials increases in volumes forcing the metals creating the noise. May be you have also observed thins pans changing shape while heating (not totally melting but some bends). Non-stick pans can be tested by observing the materials (preferably PTFE) and rubbing finger to check if it is not coarse. They will be usually sprayed gives smooth finish. The edge doesn't make a difference but always check the finishing of the pan, usually the amount of reflection from the pan, finishing.

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