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May 22, 2010 03:37 AM

Copper Cookware Thickness

Julia Child says in Mastering The Art of French Cooking that to get the full benefit of copper it "must" be 1 eighth of an inch thick. That is 3.175mm. Most quality copper cookware I have seen online seems to be 2.5mm at most.

Was Julia Child wrong? If not who sells 3mm+ copper cookware and how thick is too thick? Also do different pots and pans have different optimum thicknesses? For example stock pots?

E. Dehillerin has a line of 2.5mm-3.5mm in their downloadable catalogue but does not specify the thickness of individual items.

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  1. Matfor Bourgeat, who arguably make the best copper pots on the planet, uses 18/10 stainless steel bonded to 2.5mm red copper. Matfor claims that 2.5mm red copper gives the best connectivity and control. When asked at a trade show, Matfor engineers reportedly said that if thicker copper worked better they'd use it.

    Yes, copper stock pots are thinner than 2.5, at least all three of my tin-lined are.

    1 Reply
    1. re: GeezerGourmet

      I can see at several reasons why 18/10 stainless steel is a great choice. It is much tougher than tin, so the stainless steel will not needed to be retinned and it can be heated to a much higher temperature.

    2. Hi Stock,

      I don't own a copper pan, but I think Julia Child may come from a difference experience. A thicker pan (any materal) gives slightly more even heat distribution and better heat retention (capactiy), but worse heat response. It is possible that the stove ranges back then give off less uniform heat, so a thicker pan minimize heat spots, though I don't think it is the case.

      One would also think pan thickness should be related to the pan size. A small 6" pan shouldn't need to the same thickness as a large 14" pan.

      25 Replies
      1. re: Chemicalkinetics

        I'd like the cost and inconvenience of re-tinning not to be a consideration in this thread. I'm more interested in a pans utility for a given task. For that certain generalities have to be defined if possible.

        SS lined can be used for high heat applications. When would it be better to use a SS lined copper instead of a tri clad steel pan or any other option for high heat applications?

        Thicker copper allows for even heating with slower temperature changes. Is the difference
        in temperature change with thinner copper pots lined with tin significant enough to warrant possessing both thinner and thicker tin lined pans?

        Is it always the case that SS sticks more than tin? How significant is the difference?

        If it is significant then would there be a need SS lined copper?

        What types of cooking would require thinner or thicker copper. would there be an advantage to a pan that was thicker than 3.5mm?

        I have heard that copper pans can warp a little over time. Is there a thickness where this is no longer a concern?

        1. re: stock is my muse

          Let me offer my take on your (several) questions. Yes, certain copper foil thickesses are better suited than others for certain cooking methods. Most pans USUALLY placed on a surface hob, e.g., Saucepans, skillets, crepes, fait touts, rondeaux, and marmits should be as thick as one can find (or afford). This is because you want--to the greatest extent possible--consistent heat in and around the contents even though you are only really heating a 2-dimensional plane. In other words, you don't want the pan's contents much hotter at the pan's bottom than at the top surface. In these applications, anything under 2mm is going to hurt your cooking; anything over will help it.

          The exceptions to this rule include: double-boilers, stockpots. the so-called "soup stations", poachers, turbotiers, and the esoteic potato asperagus and stacked steamers, because with these implements, even though placed atop a hob, you DO want higher interface temperatures. and lower "upper" temps, especially when lidded. Others may disagree with the last statement, but nevertheless should agree that thicker foils in these vessels is not nearly as important as in the former. In this class, I'd recommmend 1-2mm foills. Above a certain size pan or pot--say 8 QT and above--you would want more than 1.5mm for structural and escutcheon strength, but not necessarily for functionality.

          For vessels usually intended for the oven or salamander, e.g., roasters, lidded braisers, gratins, pommes Anna, tatins, and moulds, the foil thickness doesn;t much matter, but for a different reason: modern ovens quickly heat through thick and thin copper vessels alike, and no real heat energy is being lost from the food into the room. Again, apart from structural strength, oven-use vessels may (but need not) be thinner, in the 1-2mm range.

          So, stovetop use generally =thick, oven use=thinner. But common sense also informs. I have a 5 GALLON saucepan that is just under 2mm thick. Full, it weighs almost 80 pounds! If it was 3.5mm, it would be over 100 and completely immovable. Conversely, a little 5-inch saute would be perfectly manageable if it were 4 or even 5mm thick. Ironically, American women's complaints as to the heaviness of copperware resulted in the almost complete extinction of US copperware manufacturers. Venerable companies like Waldow hung on for a few years by making thinner and thinner wares, until the advantages of copper became unrecognizable. The good news is that there is a recent reincarnation of Waldow, and their copperware is made in the USA and of VERY high quality and thickness:

          As far as warpage is concerned, I have seen only one copper pot that was not abused by high heat slightly warp. And that big 19th Century pot was abused by decades of (happy) use over open campfires with little or no under-support,

          If you have not already found copper saucepans in 3mm, if you would post your e-mail, I will send YOU (not the other "experts" posting here) a link where you can buy a NEW, 3mm, hammered, lidded, 4-piece, cast iron-handled saucepan set for under $400.

          Hope the above has helped. Good Cooking!

          I disagree that SS-lined copper can be used for true high-heat cooking. Cetainly SS will not simply flake, bubble and melt at 437F as tin does, but an empty SS-lined pan left on a hob at over 400 WILL ultimately be ruined, either by delamination or deformation. The coefficients of expansion are simply too dissimilar for it to survive very long. Better to sear in a monolithic cast iron skillet dedicated to that purpose.

          Actually, thicker (up to a point) copper on the stovetop provides for FASTER temperature changes, and therefore better heat control both up and down, and LOWER heat requirements.

          My experience is that, given the same fineness of polish, SS and tin "stick" about equally. Neither "seasons" like cast iron or enamelware. The only difference I've noticed between SS and tin in the stickiness department is that most SS-lined copper is NOT polished as smooth as tin--it usually bears fine, concentric scratches, as if it was wirebrushed or Scotchbrited wile on a rotary chuck. Scratched this way, I think SS is a bit stickier.

          1. re: kaleokahu

            Please send/post the source for 3mm copper


            1. re: analytic1000

              Hi, analytic:

              For new, try for saucepans, for frypans, and (not in their on-line catalogue. There is a link to a Bourgeat bimetal saute that is allegedly 3mm on one of the recent copper threads.

              For vintage, you must scrounge like the rest of us.


          2. re: stock is my muse

            <I'd like the cost and inconvenience of re-tinning not to be a consideration in this thread. I'm more interested in a pans utility for a given task>

            Copper cookwares utility is impacted by the lining irrespective of which you choose.
            If you ignore that you are over looking a key element.
            Cost and incovienience are major factors for a lot of buyers.

            <I have heard that copper pans can warp a little over time. Is there a thickness where this is no longer a concern?>

            Unless you abuse the cookware that's a non-issue. The 2-2.5mm copper will last a life time. Don't get sucked into thinking heavier thicker pans are universally better. There's a reason a Mauviel Zabaglione pan is only 1.2mm and the best stock pots are 3mm.
            Match the thickness and lining to your intended use. Pots that see a lot of oven use like the rondeau are often 3mm. The 2.5mm rondeaus are SS lined. Thinner pots transfer more heat.
            There are no absolute universal "bests". Neither tin or SS sticks more or less in a universal sense. If you look at tin closely there is often more imperfections than SS depending on the quality of the tin work or if the tin has blistered or has runs from over heating.
            3mm copper will heat up slower and take longer to cool than 2mm. Any time you have more mass it takes longer to transfer heat and the more mass there is the longer it will take to cool down.

            <Was Julia Child wrong? >

            Julia was opinionated. She also felt that all kitchen knives should be French Carbon steel. Does that mean every one using a SS Japanese knife has it all wrong?

            1. re: TraderJoe

              "the best stock pots are 3mm."

              I am genuinely curious about this. I was always under the impression that stock pots, when used for their intended purpose, actually benefitted for being a bit thinner. And, I have looked over a lot of copper in the last 6 months--this is not a very long time, but I have looked at lots of pots and pans in that time--and while 3mm saute pans are fairly common and 3mm saucepans are readily available, I have never seen a stock pot thicker than 2.5mm. (I will note that I did see a 10 Quart 4mm thick saucepan, which we could quibble about, but I really have never seen a proper stock pot thicker than 2.5mm.)

              1. re: jljohn

                we could quibble


                For the most part that's all the that discussion between 2.5mm and 3mm amounts to.

                If you meant to suggest a thinner stock pot is better than a thicker version why 2.5mm and not 1.5mm?

                It's unfortunate that you haven't seen a 3mm stock pot in your brief search. They are very expensive. The last one I saw was well over $1500. As I said in another thread Mauviel appears to have discontinued much of their 3mm tin lined series but IIR you felt that was incorrect as well.

                Looks like you may have found one of the 3mm tin lined items I was talking about.

                1. re: TraderJoe

                  Hi TJ:

                  I am not in a quibbling mood--it's Saturday, not Monday morning!

                  In all seriousness, when I say "stock pot," I am referring to a pot that is (a) two loop handled and (b) at least as tall as it is wide. I might add that I generally think of stock pots as being 8 qt or larger, but certainly at least 6 qt. With this in mind, that 4mm 10 qt monster saucepan is just a really big saucepan designed to make a lot of sauce. I will admit that it would function very well in place of a stock pot in most homes, but, by definition, I cannot consider it a stock pot.

                  Regarding stock pot thickness, I have generally thought that thinner is better for making stock. Of course it needs to be thick enough that the pots doesn't bend out of shape or run the risk of rivets tearing out, but, beyond that, thinner is better for making stock. Here is my reasoning:

                  First, between thin copper and thick copper, with stock, we want to put as much of the heat energy into the stock as possible. We don't want to have to heat up, and later cool down, all the extra mass of the thicker copper. Of course, for a saute, this analysis is flipped. We want the evenness of the thick copper much more that we want to avoid the energy loss of heating the extra copper.

                  Second, with long simmering liquid, the conductivity issue is minimized, because we are maintaining temp, not trying to raise it rapidly. In other words, when you saute chicken. you are trying to raise the temp of all the chicken from 40 degrees to 165 evenly, so you absolutely need the extra conductivity. With stock, once the liquid is up to temp, you are trying to keep the temperature of 200+ degree liquid stable. In this context, the evenness is much less of a concern, because currents in the liquid overcome any lack of conductivity.

                  Third, even thin copper has enough conductivity to boil water at the top edge of the pot in this environment. Let me provide an example. I have a 2.2mm tin-lined Mauviel stock pot (14 qt - 9.5" wide and 12" tall) that I picked up at TJ Maxx a while back that I really like (It is actually their large "soup station.") I have made 12 quarts of stock in it a few times, and when I crank up the heat under the pot, it will boil the water (producing bubbles) off the side walls all the way to the top of the water, 10" away from the heat source. That's plenty of conductivity for me. I suspect that thinner, even down to 1.5mm, would still do the job and still be better than clad. What I don't know is if 1.5mm could hold up to the weight without deforming.

                  Finally, because we are talking about large pots and dense metal here, thinner equals lighter, and lighter can be better and safer in the context of dealing with 25 or more pounds of simmering liquid.

                  Now, all that aside, I appreciate the 2.2mm in my pot, because that really is thick enough to build a good soup or a stew in the pot, and if one wanted a stock pot for true multi-purpose use--soups, stews, and stock, I will agree that thicker in more valuable. The limited scope of my statement is that for stock pots, as I have defined them (which I believe is how they have been defined classically), for the purpose of making stock, thinner is better.

                  I am genuinely curious to hear your thoughts on this particular point.

                  Finally, regarding the discontinuation of Mauviel's 3mm tin-lined stuff. I actually was saying that they have not discontinued "most of their tin-lined production." It appears to me that, the Rondeax aside, Mauviel stopped making 1/8" (3.175mm) copper a while ago. However, still sells a lot of tin-lined Mauviel copper (most of it is 2.5mm), and the proprietor once told me that Mauviel still makes it all, but they don't market it here, because Americans tend to want stainless-lined copper. I hope that clarifies that point.

                  The closest thing I have actually seen so far to a 3mm stocker is a Gaillard Stock pot (7" wide x 9" tall - about 6 Qt) that sold for almost $300 on ebay a while back. I'll keep my eyes open though.

                  1. re: jljohn

                    <Of course it needs to be thick enough that the pots doesn't bend out of shape or run the risk of rivets tearing out>

                    That looks a lot like what some one else posted here in the past if not a verbatim quote. I rather doubt any of the cook ware we are discussing is going to distort from it's own capacity although the vision is amusing even if well beyond absurd.

                    <We don't want to have to heat up, and later cool down, all the extra mass of the thicker copper>

                    That reasoning is flawed. The proper way to cool stock irrespective of your pot thickness is to set it in an ice bath or better yet use frozen inserts that you set in the stock.
                    This erases both your concern of residual heat and safety not only for lifting but for proper food handling.

                    Thats been discussed here in the past.

                    <if one wanted a stock pot for true multi-purpose use--soups, stews, and stock, I will agree that thicker in more valuable>

                    That really allows us to cut through a lot of the minutia doesn't it.
                    I rather doubt many cooks are so restrictive in their view as to never make soup, chowder etc in a stock pot or Heaven forbid make stock in a ......soup pot.

                    <What I don't know is if 1.5mm could hold up to the weight without deforming>

                    Keeps it real.

                    BTW the 3mm Mauviel stock pots were tin lined.
                    The bottom line is that in a universal sense and with out getting so literal we have to do a line by line numbering of the caveats thicker copper in a stock pot would be better.
                    The practical question is will the performance of an extra .5mm or for that matter will copper Vs aluminum or SS show enough performance gain to justify the cost?
                    The answer from my perspective? It depends. I've had the 3mm copper in more than one kitchen and it was truly great stuff but inherited from a previous Chef. If your making stock and soup every day and/or just want the best and money is not a factor...sure why not.
                    At home I find aluminum and SS works just dandy. I'd love to justify even 2.5mm on a stock pot but my knife fetish wins over my desire for more copper every time.
                    If you do find a 3mm stock pot at a favorible price grab it if you can. They are getting very hard to find as you've already found.

                    1. re: jljohn

                      Are you a Mauviel distributor or representative?

                      1. re: AuntieMame58

                        Hi, Auntie:

                        If my friend Jeremy is a Mauviel agent, he is operating under deep cover.

                        I am interested in the line from Villedieu you say is coming to USA. Can you tell us about it? Is it an old line or a new one? What sets it apart from the competition or recommends it? Is it more affordably priced than Mauviel, Falk and the rest?


                    2. re: jljohn

                      Hi, Jeremy:

                      The best stockpots *are* thicker. But except for having thick bottoms to give even heat for sweating mirrepoix and browning bones, etc., and having the structural integrity to handle their own size and full-loaded weight, there is now little need. I like to say that thick copper is always better, but the marginal return on stockers is low. Unlike another here, I think copper >2.5 mm shines in all stovetop and most oven applications, especially where the benefits of copper's high specific heat are desired. Again, it is the marginal return that differs with preparations.

                      Since we were talking about that strange trivet-bottomed pan in another thread, we would do well to step even further back in time--to open hearth cooking. Large thick copper marmites received their often inadequate heat from their sides as well as the bottoms, and had to move it maximum distances to squeeze every available calorie from the fire (and as quickly as possible--simmers were easily lost, and took longer to return in cast iron). Visualize a crane and trammel, swung deep into the hearth, with the fire's variable heat rising all around. Or perched on a legged trivet at the side of the fire.

                      But in our time, when you can have a modern, powerful, consistent, instantly- and widely-adjustable two dimensional heat source and disk-bottomed stockers for very little money, the importance of highly-conductive sidewalls on stockers has faded for non-viscous liquids like stocks. I think it still has a vestigal advantage when cooking on gas (for the same reason--as there are Btus still to be grabbed), and my experience with large stockers (e.g., 5G and up) on underpowered home hobs is that thick copper will help the largest pots boil, and all pots boil faster. But IMO, these factors are not a good reason to part with $1,500 and develop the upper body strength to hoist around 20 extra pounds when scalding liquids are inside.

                      Fear not, I believe Mauviel still makes thick copper stockers--in sizes up to 800L. A year or so ago, there was a large Mora stocker sold on eBay that was 6mm. I think it went for only $500. My 10 Imp. Gallon Elkington was $185, so I couldn't resist.


                      1. re: kaleokahu

                        Hi TJ and Kaleo,

                        Thanks for the responses. I'll say this about it--while I do concede to the general rule that, with copper, thicker tends to be better, and I do accept the historical value of thick copper stockpots, and I acknowledge that most people want stock pots for much more than stock making, I am not convinced (as a theoretical matter) that the best stock pot for making stock (remember that my point has always been limited to this) is a thick stock pot. However, I know that you both have vastly more experience with copper cookware than I, and you both have actually used thick copper stock pots. So, I'll take your word for it and keep my eyes peeled for one to try for myself.

                        Now, for two followups:

                        TJ-- "<Of course it needs to be thick enough that the pots doesn't bend out of shape or run the risk of rivets tearing out> That looks a lot like what some one else posted here in the past if not a verbatim quote. I rather doubt any of the cook ware we are discussing is going to distort from it's own capacity although the vision is amusing even if well beyond absurd."

                        Truth be told, I don't remember reading that here, although it is entirely possible. However, when my 14 qt pot, mentioned above, is full, it flexes quite a lot when I pick it up. The round 9.5" opening flexes to an oval with only a modest amount of inward or outward pressure. Now, I am not saying that that 2mm is anything to worry about, but I see a lot of 1mm copper pots and pans listed on ebay. Imagine a 12.5" x 12.5" stock pot made of 1mm copper. Are you really telling me that it is laughable or absurd to think that such a pot might not deform at all when being carried with 60 pounds of stock in it?

                        Kaleo--"my experience with large stockers (e.g., 5G and up) on underpowered home hobs is that thick copper will help the largest pots boil, and all pots boil faster."

                        I understand why an underpowered hob will boil water in a large thick stock pot that it could never boil in a thin stock pot, but how is it that your last clause it true. Allow me to posit this: I have a 4mm thick 8Qt copper pot and a 1mm thick 8Qt copper pot of the same interior dimensions and capacity, if all volumes, temps, and applied BTU's are the same, doesn't the thinner pot boil faster as the thicker pot has more mass to heat, and hence a greater percentage heat goes to the pot instead of into the water vis-a-vis the thin pot?

                        Oh, and TJ--we appear to have opposite problems. Every time I really start to eye one of Takeda's Gyutos, I take a hard look at my current knives and decide they'll do me just fine, and then I buy a copper pan instead.

                        Thanks Guys,


                        1. re: jljohn

                          If the stock pot is only used for stock, or other thin liquids, all that really matters is the bottom. With a reasonably thick bottom of any material there is no need for copper's conductive properties on the sides of the pot. The broth, or other thin liquid, efficiently conducts the heat. Even a pure stainless steel stock pot is viable as heat from hot spots within the pot causes the liquid to flow, mix and equalize. The worse case scenario for the stock is some of the mirepoix might stick. If you are later reducing the stock to a glace de viande, copper is still your best friend.

                          1. re: jljohn

                            "Are you really telling me that it is laughable or absurd to think that such a pot might not deform at all when being carried with 60 pounds of stock in it?"

                            What I'm telling you is that the false scenarios you are creating are just as absurd as the first person that posted that other bit nearly word for word a few years back. The 1.5mm copper pots are a bit thicker than tin foil. They are not going to collapse on them selves nor are the handles going to tear through the sidewall.
                            Water weighs a titch over 2# a quart. Filled to the brim your 14 gt will hold 28#. Of course you will have less liquid and other items in your stock but a 14 qt pot will hold closer to 30# not 60.
                            The extreme exaggerations to create a hypothetical failure are just a bit over the top. I think we all understand most items can be deliberatly abused into failure.
                            You want to insist thinner is better but eschew main stream 1.5mm Mauviel stock pots for those even thinner on flea bay. All of this to debate a theory between 2.2/2.5 mm and 3mm?
                            Largely that is just minutia for the sake of quibbling although the thicker pots are better especially in the larger capacity pots that are taller.
                            Setting theory aside lets remember that stock pots do get used for more than just stock in the real world.
                            I'd put a lot more focus on expense, physical dimension and lining not to mention brand and warranty if you truly are this worried about catastrophic stock pot failure.
                            No matter what you buy just use it and enjoy it.

                            1. re: TraderJoe

                              <a theory between 2.2/2.5 mm and 3mm?>

                              It is rather absurd to say 3 mm is good, but 2.5 mm is bad. We are not talking about speed limit here. Physical property changes in a continuous manner, not quantized. As such, there isn't a cut off number. A pot made out of a 2.5 mm will transfer heat faster, while a pot made out of a 3 mm will be more evenly heating. It isn't a "on and off" switch here.

                              1. re: Chemicalkinetics

                                It is rather absurd to say 3 mm is good, but 2.5 mm is bad


                                Did I say that? I think not.

                                1. re: TraderJoe

                                  Not you. I was reiterating your earlier point.

                                  1. re: Chemicalkinetics

                                    I was reiterating your earlier point

                                    Whoosh! I thought I was loosing it. LOL ;)

                                    1. re: TraderJoe


                                      Reading what I wrote, I can totally see how confusing I was. I should have been more clear and stated that I was trying to agree with you. No, you are definitely not losing it. And for those of us who are going to "lose it", I wonder if it is better to start losing the mind first or losing the body first. I opt for the later when the time comes -- not that I get to pick anyway.

                            2. re: jljohn

                              Hi, Jeremy: I should have said "...and all pots *regain the boil* faster." If you're blanching vegetables in an 8Q or an 80Q, the thick version retains more heat after the dump.


                              1. re: kaleokahu


                                That makes sense; thanks for the clarification.

                                Have a great day!


                        2. re: TraderJoe

                          In other threads this has been discussed, but my brain went on strike at the time:

                          For rondeau/oven dwellers, isn't thicker better exactly for that retention of heat?

                          1. re: TraderJoe

                            "and the best stock pots are 3mm. .."
                            Huh? Didn't K just discuss this being the other way? Convection is convection, and why worry about weight (and cost)?

                      2. How much does the thickness of the pan sides matter? I saw a cute (and very inexpensive) Baumalu 2Q copper saucepan (about 6.5" diameter and 3" high) with only 1-1.5mm sides but the bottom feels heavier - i'd guess 2-2.5mm.

                        I'd be using this for sauces and possibly heating up food, etc.

                        Should I instead look for a pan that is 2.5-3 mm all the way up the sides?


                        7 Replies
                        1. re: iyc_nyc

                          iyc_nyc: Your question is somewhat moot because these pans are made by forming same-thickness copper (or bimetal) sheets using lathes and chucks. Therefore, it is highly unlikely that the Baumalu you saw has a thicker bottom than sides.

                          Thickness is hard to judge visually. If you don't have a micrometer, you can use coins to compare. A thin US dime is 1.35mm, so 1 mm is actually very flimsy (It actually feels like you can bend it with your hand). A penny is 1.55 mm, and a nickel is 1.95 mm. The Eisenhower Dollar coin is 2.58 mm thick.

                          1.5 mm is about the minimum that is worthwhile and structural. 1.5 mm-2mm is considered "table service" grade, and the snootiest cooks probably wouldn't cook in it. 2.5 and up is best, and yes, I believe good conduction up the sides is important in a saucepan. Still, a 1.5 mm copper pan will perform better "up the sides" than will other materials of the same thickness. For comparison of even heat, consider the following "optimal" equivalencies:

                          Copper 2.82 millimeters thick
                          =Pure Aluminum 5 millimeters thick
                          =Cast Aluminum 8.03 millimeters thick
                          =Steel 16.56 millimeters thick
                          =Cast Iron 22.08 millimeters thick
                          =Stainless Steel 53 millimeters thick

                          Hope this helps.

                          1. re: kaleokahu

                            Thanks, amazingly helpful. Re: the comparison of even heat among metals, is this relationship consistent as the thickness shrinks/grows -- or, for example, does copper lose its relative advantage when it gets too thin?

                            The challenge with gauging the thickness of the Baumalu pan without a micrometer is that the sides are rolled (like the new all clads) -- and I read somewhere that you can't just measure the edge of such pans b/c they are cut at a slant and so could be misleading. Do you know anything about that -- ? The pan looks like this one, but one size smaller:

                            (And the Baumalu really does feel heavier on the bottom -- odd sensory illusion!


                            Thanks again, Kaleokahu (and anyone else who can weigh in..)

                            1. re: iyc_nyc

                              generally speaking if a copper pan rolls the edge it's because the copper is very thin and a rolled edge provides more structural rigidity. there are exceptions to this of course, i believe faulk rolls the edges on one of their lines, mind you a very nice and expensive line. I would see that pan as still usable, but to harness the full potential of the even heating of copper you're going to want another millimeter of the red stuff between your heat and the food.

                              here are a couple of excellent explanations, they do a much better job than i could ever attempt at explaining the thermal properties. hope this helps :)

                              (scroll down to "what materials are used"

                              1. re: cannibal

                                Terrific and very helpful - thanks so much! (am completely new to copper so appreciate these primers :-))

                              2. re: iyc_nyc

                                iyc_nyc: You're welcome.

                                The numbers were the results of solving the equation: thickness of metal x thermo-conductivity coefficient = 2.65 (THERMCO). So the relationship is consistent. However, the thinner the copper gets, the less of it is there to conduct heat laterally and vertically away from the heat source, and therefore the greater the likelihood of hot spotting. That's why most clad with a thin copper layer is a cynical joke.

                                I don't know about the Baumalu rolled lip per se, but what you have read makes sense--if the turned-out lip edge is finish ground parallel to the pan bottom, then it would measure out at greater than the true foil thickness. It's the equivalent of cutting the foil on a bias. If you want to be sure of the wall thickness, you probably need a caliper or micrometer that will span the curvature of the lip.

                                But another cheap trick is to compare the pan's weight with one of the same size and a known thickness. I'm not at my country house tonight with my 6.5"x3"x3mm pan, but I do have here in the city a 3mm tinned pan that is 7&1/8"x3&1/4 (2&1/4Q brim-full), and that pan weighs 4.75 pounds. So if the Baumalu isn't tipping the scales somewhere >2.5 pounds, it's pretty thin.

                                1. re: kaleokahu

                                  Re: your first para, then does that mean a smaller (in surface area) pan can 'get away with' a thinner copper, since the heat needs to be conducted a smaller distance than with a larger pan?

                                  Thanks for going thru the trouble of weighing your 3 mm pan. In comparing the Baumalu with yours, does it matter that the handles on this one vs yours might be different? (the Baumalu handle is cast iron)

                                  1. re: iyc_nyc

                                    iyc_nyc: "...get away with..." Yes, I think to some extent. But if you're cooking on gas, going thinner isn't a good idea.

                                    My handle was cast iron as well.

                          2. ques out of the blu--
                            were older French cast iron handle william sonoma decent thick?

                            pardon typing.

                            7 Replies
                            1. re: rbraham

                              I have two mid-seventies vintage W-S saucepans, both between 2.5 and 3 mm thick. The CI handles are hefty.

                              1. re: rbraham

                                I have one old WS saute with cast iron handles, and it is 1/8" thick (a little over 3.1mm). I think that's decent. :)

                                1. re: rbraham

                                  Hi, Rob:

                                  Most were, originally. Less so as time went on and W-S became less of a cook's store and more of a chain. Current stock (all Mauviel and Ruffoni) that is readily available here is no thicker than 2.3mm of copper bimetal. There are some hard-to-find counterexamples, and new old stock.


                                  1. re: kaleokahu

                                    I agree. I liked it when W-S and SLT were truly stores for cooks, the closest thing in the USA to one thing like Dehillerin. I am suspicious of my local W-S. the only pieces of copper they offer are a coucoussier and a couple of pretty but thin Ruffoni pieces. They don't generally often things I think of as basics, like those little two or three dollar tab handle peelers (they'll sell you a set of 3, only one of which is a plain peeler) or French wooden spatulas (unless you'll pay twenty dollars for one of olive. A third of the store is table linens and decorations, tableware, and glass ware, a third is cookwares, and the remainder is for hawking ready made food, oils, prices, etc. if I want tapenade or mushroom soup, sell me the tools I want to use to make them. Fortunately for me, except for a few items that don't last forever, like cheap peelers, I am well supplied. If I were setting out now to amass my collection, very little would be done at W-S or SLT. I'd be online to places like Fantes or Dehillerin or on eBay or Princes or buycoppercookware or locally at Ace Restaurant or the aisles of Central Market. My advice to people who know and seek fine cookware, just sty alert and grab it when you find it. I am still kicking myself over a heavy copper poacher that was reasonably priced and was on top of a shelf in a local gift and stationery shop!

                                    1. re: tim irvine

                                      Well said, Tim.

                                      I've been scrounging on ebay for years to amass my batterie de cuisine. Do you need a hand hammered, long fish poacher? I have an extra made by Matfer Bourgeat from the 1960's, quite heavy, only used once in all these years. I'm in the middle of moving, and my wife says we don't need two of these.


                                      1. re: alarash

                                        Thanks kindly but I have since picked up an old BIA poacher, tinned steel, for $16 on eBay. It is only about 16", but we don't need anything larger. I can envision a baby salmon in it now, marinated in gin, poaching, getting ready to be napped with beurre blanc.