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Thinking to conduct a "frying pan shoot-out" -- seeking advice

tanuki soup Aug 29, 2011 03:18 AM

Hi, guys:

I just received a de Buyer Prima Matera frying pan from the USA today. It's an induction-capable copper frying pan -- 1.8-mm copper layer on the outside, 0.2-mm stainless steel layer on the inside, and a 1.0- to 1.5-mm-thick magnetic steel base fused to the bottom to make it work on an induction cooktop. (See the first two pictures below.)

If people here are interested, I was thinking to conduct a frying pan shoot-out to evaluate various types of frying pans in terms of speed and evenness of heating on an induction cooktop (third picture below).

The contenders that I happen to have in my kitchen (fourth picture below, clockwise from top center) are as follows:

1) de Buyer Prima Matera copper/stainless steel frying pan: 26.5 cm in diameter, weight 1682 g
2) Archetun induction-capable aluminum frying pan: 26.5 cm in diameter, weight 1116 g
3) Silit Silargan stainless steel/ceramic frying pan: 25.0 cm in diameter, weight 1692 g
4) TKG Pro carbon steel frying pan: 28.0 cm in diameter, weight 1380 g
5) Mario Batali enameled cast iron frying pan: 26.0 cm in diameter, weight 2465 g

The plan is to place each of these pans (cold) on the induction cooktop, turn the heat to medium, and measure the temperature at the center of the pan, about an inch from the edge of the pan, and at a point halfway between the two. I'll use a non-contact infrared thermometer (pistol type with a laser pointer) to obtain these measurements every 1 minute over a period of 5 minutes or so. Finally, I was thinking to take a final set of measurements at 10 minutes after turning off the heat in order to evaluate heat retention.

Would anybody be interested in the results of such a test? Is it worth the effort? Any thoughts concerning the basic methodology? Any suggested changes/additions to the testing procedures?

Looking forward to any feedback. Thanks in advance for your help.

Tanuki Soup

 
 
 
 
  1. d
    dlmz06 Mar 8, 2013 03:40 AM

    Love my IR gun. I just store mine nxt to the stove. Costs of the guns should drop next year since integrated small cheap MEM IR sensors began to be produced in volume this year. For .example see http://www.ti.com/lit/ug/sbou107/sbou... which also has a nice emissivity chart for differnt materials . I like to put a little water or oil in the bottom of the pan about a half centimeter or quarter inch or more when looking at my induction cooker temp control function to always have the same emissivity to compare. Shiny steel pots, shiny copper shiny or brass read low. Old oxidized dirty pots read pretty good. So point it at dull dark food, water , oil (more than just a film) , or dark carbon steel or cast iron when you want accuracy.

    1. davidahn Jan 11, 2012 10:07 AM

      Tanuki Soup,

      I just found this thread, and I'm mighty intrigued! To be honest, I'm a little disappointed (but not surprised) that Prima Matera's performance is only marginally better than the aluminum pan's. I'm not surprised given the small margin of superiority of copper over aluminum in thermal diffusivity (120 x 10^-6 m2/s vs 100 versus 100, or 1.16/0.94, depending on source).

      Soooo... you wouldn't happen to have access to any fully clad pieces to test, would you? I've tentatively decided on All-Clad's Copper Core (I've only purchased one piece, hasn't even arrived yet) and would love to see how it stacks up to Prima Matera. Kaleo is suggesting I look hard at the Prima Matera, and referred me to you. PM is beautiful new, but I'm leery of the maintenance hassles of copper vs. the all stainless exterior of AC.

      So how about it? All-Clad Copper Core, and while you're at it, a fully clad aluminum piece? Please?!?

      David

      8 Replies
      1. re: davidahn
        tanuki soup Jan 12, 2012 02:35 AM

        Hi, David:

        Glad to hear that you're interested in de Buyer Prima Matera pans. I posted a reply to Kaleokahu a while ago reporting my initial impressions. The link to that post is (I hope) here:

        http://chowhound.chow.com/topics/8210...

        As for maintenance and cleaning, it's no problem at all. The copper outside of the pan does discolor a bit after you've used it, but light rubbing with a soft sponge and a bit of Kleen King Stainless Steel and Copper Cleaner brings the beautiful shiny copper surface right back. Seriously, we're talking 20-30 seconds of light rubbing at most.

        Sorry, but I don't have access to any All-Clad Copper Core cookware. I do have a variety of fully clad stainless steel/aluminum frying pans, but unfortunately none of them are the same size as the Prima Matera pan, so I don't think any measurements I could obtain with my IR thermometer would have much meaning. I would, however, be interested in hearing your impressions of your new Copper Core pan.

        Actually, I scanned through your other post concerning Copper Core last night, but didn't respond there because I didn't think I had much to contribute. However, I very much agree with one poster in that thread who pointed out that, in the real world, the difference between aluminum and copper is much less important than other considerations (except, I suppose, for certain specialized applications like candy making).

        I certainly don't mean to dissuade you from picking up a beautiful Prima Matera frying pan, but looking back on this "frying pan shoot-out" now that several months have passed and I am both older and wiser (joke), I would assign less importance to minor differences in thermal measurements and more importance to practical considerations such as size, weight, balance, handle comfort, helper handles, rolled pouring edges, ease of cleaning, etc., etc.

        Best regards,

        TS

        1. re: tanuki soup
          davidahn Jan 13, 2012 01:08 AM

          Tanuki Soup,

          Thanks for your link. Kaleo kept mentioning your Prima Matera review but I couldn't find it!

          As my wife is the primary cook in our kitchen, I really need to stop making the kitchen decisions! (She really doesn't want the induction burners, but I told her I'd use them, she doesn't have to.) While her impatience would appreciate the immediate heat response, her rough handling would truly test the scratch and dent resistance of copper. Are you rough on your pan, have you dropped it yet, and does it show any nicks, dents, or scratches yet?

          I really feel that on balance, my wife would really like nothing more than a cheap aluminum core SS clad set á là Tramontina. The All-Clad Copper Core would be a nod toward my technical geekery. The near-indestructibility of SS would be a huge plus, and the ability to throw them in the dishwasher is not a small advantage. (I hear the copper band tarnishes in the DW; I hope I can easily polish that copper band by hand.)

          You say your assessment would be different now a few months in. In what way would you change your assessment in comparison to other pieces you own, or how would you change the Prima Matera to make it perform better? How do you rate its size, weight, balance, handle comfort (PM's looks OK in the photos), flared lip (noticed absence in PM), ease of cleaning?

          David

          1. re: davidahn
            tanuki soup Jan 13, 2012 02:20 AM

            Hi, David:

            Although I continue to be very impressed with the technical performance (amazingly fast response, very even heating) and relatively easy maintenance of my PM pan, there are several reasons that it's not my "go to" pan.

            (Oh yeah, before I forget to answer your specific questions, the weight and balance are excellent and the handle feels great in my hand. I'm pretty careful with my cookware, so no nicks or dents, but a few minor surface scratches on the outside -- I could probably buff them out if I were so inclined.)

            First off, by way of explanation/introduction, I like using all different kinds of cookware -- carbon steel (TKG, which is a Japanese restaurant brand), cast iron (Lodge, Lodge Signature, Iwachu from Japan), enameled cast iron (Le Creuset, Mario Batali, Lodge), induction-capable aluminum nonstick (De Buyer CHOC induction, Swiss Diamond, Vollrath, Archetun, Infinite Circulon, Fagor), ceramic-coated stainless steel (Silit Silargan), stainless steel (TKG, EBM, Fissler, Mauviel M'Cook, De Buyer Affinity, All-Clad, Le Creuset, Tramontina, Brabantia, Calphalon Contemporary), etc. To me, each material has its own advantages and disadvantages for specific cooking tasks.

            The only reason I wanted to try out stainless steel pans is because I'm becoming interested in making pan sauces and gravies (i.e., deglazing). Specifically, I like to fry up a mess of pork chops or pork cutlets and then deglaze the pan to make a nice thick pan gravy.

            Given the above, the reasons the PM spends a lot of time on its hook are:

            1) It is a bit too small (11 inches). When frying up a batch of pork chops, I think it's important to avoid overcrowding the pan.

            2) It doesn't have a pouring lip. When I pour off the excess fat before deglazing the pan, it runs down the side. Same for pouring off the gravy after deglazing.

            3) It doesn't have a helper handle, which is handy for extra stability when pouring the fat off into a jar for storage/disposal.

            4) It doesn't have a lid.

            So my "go to" stainless steel frying pan is currently a Le Creuset Tri-ply -- a roomy 12.5 inches in diameter, a very effective pouring lip, a convenient helper handle, and the domed lid from my All-Clad paella pan fits it perfectly. Basically, it works quite well for its intended application. The only thing I don't like about it is that it feels a little too light and cheap to me. I'm hoping that a Viking 7-ply pan I recently ordered from the US will be heavier and more substantial.

            For frying up green peppers or browning onions, I prefer carbon steel.

            For eggs (especially omelets) and fish, I like nonstick aluminum.

            For braising, I use enameled cast iron.

            For steaks, nothing beats a cast iron grill pan.

            For things I want to cook in heavily salted water (e.g., asparagus), I use ceramic-coated stainless steel (no risk of pitting).

            Finally, with regard to stainless steel, I like fully clad for frying pans and small saucepans and disk bottoms for pasta pots and stockpots, as discussed in the Demeyere video that I believe you've already looked at.

            I guess this long (and perhaps rather boring) explanation is just meant to illustrate my point that even though the PM may be the "best" pan I own (and was definitely the most expensive), it's probably the one I use least often. If it were an inch or two larger and had a pouring lip and a helper handle, it would be PERFECT for my needs. Unfortunately, it would also probably cost $600.

            Hope you find these random musings helpful. Have a great time shopping for some nice new cookware -- although it often seems impossible to decide among the seemingly infinite number of attractive choices!

            Best regards,

            TS

            1. re: tanuki soup
              davidahn Jan 13, 2012 11:47 AM

              Tanuki Soup,

              On the contrary, I found your musings very interesting indeed! Thank you.

              If you have scratches with GENTLE use, Prima Matera is NOT for my wife! It won't stay gorgeous for long in OUR kitchen. Plus, as beautiful as PM is, the stratospheric prices of the larger Stewpots are hard to justify considering the limited benefit of copper sides and the lack of flared pouring lip. Now the Frypans, mind you, are a much more attractive price-performance proposition.

              So you have quite the arsenal of cookware. I'm glad to see your go to frying pan is a fully clad aluminum core, as the A-C Copper Core should do equally well or slightly better (hopefully). I'm no longer completely anti-nonstick, so I'll have to see how well or poorly the SS does with eggs. I just bought a carbon steel wok, so I'll compare SS to that for veggies. I'm also very interested to try true wok cooking, only sautéing on high in a nonstick aluminum wok… As for braising, steaks, etc., we're nearly vegan so your cast iron pots/pans are less applicable unless we find other uses for them. We do have a Le Creuset enameled cast iron dutch oven still in the box; we'll have to see what that's good for in our particular kitchen. And yes, that Demeyere video you refer to did convince me to order the copper disk bottom pots (Nouvelle Copper Stainless).

              If you had a Saucepan or Stewpan of sufficient size, 3.5 qt, say, would you use it a lot more, or a little more? I'm sure the pouring would still be an issue. The reviews are mixed, but this might save a great pot from being shelved: http://www.amazon.com/RSVP-Silicone-S...

              I'm sure Kaleo is fed up with me by now due to my ceaseless waffling, but I could not seem to decide between A-C Copper Core and the Prima Matera, mainly because of my wife's and my dueling needs. But I had a minor epiphany: we have a kitchen capable of accommodating 2-3 chefs; why not get the Copper Core for my wife and Prima Matera for me? I don't have to commit to a whole kitchenful of both lines, and if I really don't like them, I could sell the pieces.

              Thanks so much for your insights and experiences!

              David

              1. re: davidahn
                e
                ellabee Jan 13, 2012 02:45 PM

                Wrt your Le Creuset Dutch oven still in its box: can't see how being vegetarian or vegan would affect the usefulness of this piece; don't you make soups? Stews? (e.g., ratatouille) Also great for long, low-simmered things like applesauce, apple butter, homemade ketchup. I'm assuming this is 4 to 6 quarts, not the 7-9 quart monsters.

                It's fine on induction as well as flame or radiant electric. You might want to be the one who cooks in it if your wife bangs things up as much as you say. The biggest risk to the enamel comes during washing.

                1. re: ellabee
                  davidahn Jan 13, 2012 10:17 PM

                  It's in the box because my wife's never taken it out. She may be waiting until our new kitchen is completed, I don't know. Thanks for the ideas on what to do with it!

                2. re: davidahn
                  tanuki soup Jan 13, 2012 03:52 PM

                  Hi again, David:

                  I agree with you that a Prima Matera frying pan makes a lot more sense than a PM stockpot or stewpot. For the latter, a good-quality stainless steel pot with a nice thick aluminum disk covering the entire bottom out to the edges would be a better choice IMO.

                  Demeyere Atlantis looks really, really appealing to me. Fissler is very nice, optimized for induction, and not too outrageously priced. I am also a big fan of Tramontina -- it's not as "kitchen jewelry" as some of the other options, but good quality, intelligently designed, and built like a tank. You could get an extensive selection of Tramontina cookware for the price of ONE small Prima Matera frying pan. You would definitely NOT hesitate to hand your wife Tramontina pots and pans, not only because they are so solidly built, but also because they are so reasonably priced that you're not going to lie awake at night worrying about them.

                  I'd be interested to hear your impressions of the Nouvelle Copper Stainless pot as well as the Copper Core.

                  Carbon steel is great for sauteing vegetables in a bit of oil or butter.

                  I agree with ellabee that a Le Creuset French oven would not be out of place in a vegetarian kitchen -- bean dishes, lentil soup, and vegetarian chili immediately come to mind.

                  Your final conclusion makes a lot of sense to me. There is absolutely no reason to make a blanket decision on your cookware needs and get all of the same kind or buy it all at the same time. I'd suggest that you pick up a selection of basic Copper Core pieces that are suitable for making your favorite recipes. You could also initially get one piece of Prima Matera just to try it out. If you LOVE it (My Precious!), add more later. That's why I have such a diverse collection of cookware. I notice that the pot or pan which I've been using to prepare a certain favorite recipe is unsatisfactory in some way, so I try to find a pot or pan that is ideal for that specific recipe. For example, I have a casserole that I think of as "the chicken cacciatore pan", a large nonstick frying pan that is "the trout pan", and a small stainless steel pot that is "the tempura pot".

                  So yes, don't commit yourself now, but extend the interesting and enjoyable process of shopping for and buying new cookware over months, years, or decades.

                  Have fun!

                  TS

                  1. re: tanuki soup
                    davidahn Jan 13, 2012 10:22 PM

                    I hope the 90% coverage copper disk of Nouvelle Copper Stainless Steel is almost as good as the Demeyere Atlantis's full coverage; if not, I'll be back here whining about it. LOL I'll let you know how it goes.

                    It's great to have so much experience and insight available here as I start my journey. I'll keep asking you guys questions, you can be sure of that!

        2. tanuki soup Sep 16, 2011 07:00 PM

          Hi, Guys:

          Now that everyone has completely lost interest in this thread, I'd like to post my new measurements for the de Buyer Prima Matera induction-capable copper/stainless steel frying pan.

          These new measurements were obtained using a new IR noncontact thermometer with the emissivity set to 0.14 (the most common published value I could find for "machined stainless steel"). The new graph is much more believable than the old one, which was obtained with an incorrect emissivity setting of 0.95. Also, to double-check the readings, I flicked some water into the pan every now and then during the test, and was pleased to see that the water didn't boil at readings under 100C, but did at readings above 100C. Finally, I should mention that It was a bit of a challenge to get consistent measurements with the emissivity set to 0.14, because the readings tended to jump around a lot more than in the earlier tests. I did the best I could.

          For convenience, the graphs for all of the pans are shown again below. Only the graph for the Prima Matera pan has been revised.

          The Prima Matera and the Archtun induction-capable aluminum pan are now really close to each other. Compared with its original (incorrect) graph, what the PM loses in "bunching" of the curves (even temperature distribution), it gains in the height of the curves (fast temperature responsiveness), which is, after all, another of the major benefits of copper.

          Thanks for your patience. Hope you find this information interesting.

          Tanuki Soup

           
           
           
           
           
          8 Replies
          1. re: tanuki soup
            c
            careme_fan Sep 17, 2011 03:11 AM

            Very interesting! Thanks TS. So it seems Prima Matera is really fast -- it needs only 3.5 min rather than 5 for Archetun to get the center to 150C with the edges not too far behind. I am getting a serious case of pan envy -- all I have are mundane 3-plys and aluminum disk bottom :-) BTW, your notes say that the PM is 26.5 cm diameter. Is this model 6224.28 (nominally 28 cm) or 6224.24 (nominally 24 cm)? Similarly I guess the Archetun is a nominally 28 cm as well?

            Thanks again! -- CF

            1. re: careme_fan
              tanuki soup Sep 17, 2011 04:03 AM

              Thanks, careme_fan:

              Yes, the Prima Matera is the nominally 11" (28-cm) model (6224.28), and the Archetun is listed as an 11.5" (also 28-cm) model.

              I used a tape measure to roughly measure the sizes for my initial descriptions -- just measured them again more carefully: the PM is 26.8 cm from outer edge to outer edge, and the Archetun is 27.2 cm, but with thicker walls because it's aluminum.

            2. re: tanuki soup
              k
              kaleokahu Sep 17, 2011 08:35 PM

              Hi, tanuki:

              Lost interest? Not a chance! Keep up the good work.

              Now get a converter disk, and run a straight-gauge 3mm tinned copper pan in the race.

              Cheers,
              Kaleo

              PS I think your "edge" traces would bump up appreciably on a gas hob.

              PPS Is your cooktop *really* 10.7 kW? Can you run it with Fukushima off line? LOL!

              1. re: kaleokahu
                tanuki soup Sep 17, 2011 09:13 PM

                Hi, kaleo,

                Thanks for the post -- and for the continued interest. I agree that the edges would get hotter on a gas hob due to the hot gasses flowing up along the sides of the pot. That's probably one of the big disadvantages of induction. OTOH, it also means that pot handles never get hot (even the loop handles on pasta pots) and that the kitchen tends to stay cooler. OTOH OTOH, you need a powerful range hood because you don't get a strong updraft to help pull the cooking steam up to the exhaust fans.

                Sorry, but I really don't like the idea of the converter disks. I've read a number of extremely negative reviews of those things -- very inefficient, cooktop overheats and shuts down to protect itself, etc., etc.

                If I really need to use something that isn't suitable for induction, I have a handy little countertop gas ring (12000 BTU) that I can hook up to the gas outlet for my freestanding gas oven. Alternatively, I'm still fascinated by those new "All Metal" induction cooktops from Panasonic. Given the price of the Prima Matera cookware, it might be worth it to upgrade the cooktop to one that can handle regular copper pans.

                My cooktop is 6-7 kW total -- one 3.0-kW induction burner, one 2.5-kW induction burner, and one little 1.2-kW halogen burner. It's a 200-V unit that operates at twice the standard Japanese line voltage of 100 V (I guess equivalent to a 240-V unit in the US).

                PS. I think the (corrected) graphs fully support your love of copper cookware. Copper clearly provides the fastest responsiveness and the most even heating. If only it were cheap, light, dishwasher safe, easy-care, and nonstick -- well, I guess you can't have EVERYTHING! ;-)

                1. re: tanuki soup
                  k
                  kaleokahu Sep 17, 2011 09:24 PM

                  Hi, tanuki:

                  Yes, there seem to be tradeoffs with everything.

                  I would very much appreciate any citations you have to reviews--pro/con/indifferent--of the converter disks for induction. I have not come across any.

                  Isn't a Prima Matera just a copper pan with its *own* converter disk?

                  Aloha,
                  Kaleo

                  1. re: kaleokahu
                    tanuki soup Sep 17, 2011 09:51 PM

                    Well, not exactly scientific, but here are the 1-star and 2-star reviews of the only induction converter disk available at Amazon:

                    http://www.amazon.com/Max-Burton-6010-Induction-Heat-Proof/product-reviews/B00213L3PK/ref=cm_cr_dp_hist_1?ie=UTF8&showViewpoints=0&filterBy=addOneStar

                    http://www.amazon.com/Max-Burton-6010...

                    I understand your comment about induction-capable aluminum and copper pans essentially being pans with a converter disk stuck to the bottom, but I suspect that the thermal conduction is significantly reduced if the heat has to cross over even a microscopic gap. I've read that electrical conductivity and thermal conductivity tend to closely parallel each other because they are both based on the high mobility of electrons in metals. I wonder whether the poor performance of converter disks is due to the discontinuity in electron flow -- similar to a cracked or cold solder joint (even if you can't see the hairline crack, the electricity won't flow).

                    1. re: tanuki soup
                      k
                      kaleokahu Sep 17, 2011 10:24 PM

                      Hi, tanuki:

                      Thanks. Many of these reviews are pretty funny, in a painful sort of way. I'll note, though, that there were more 5- and 4-star reviews than lower ones.

                      As you probably know (and bemoan), I'm *not* one to defend induction. Many here might think I lash out at it at every opportunity. In past "lashings", I've been chastened not to throw the baby (induction technology) out with the bathwater (faulty detection circuits--e.g., Viking's old incompatibility with Le Creuset). Now, it is I who is asking the charitable question: Might not the problem these 1-star reviewers are having be just a detection issue?

                      I also detect (really, no pun) that folks get mighty pissed off when they spend $50 (I think a French maker charges north of $100) for a thin circle of ferritic steel, and it shuts down their new $3,000 Food-A-Tron. Who would blame them?

                      You are 100% right that the lack of a firm bond between the disk and the pan will tend to decrease the efficiency of the heat exchange. To some--as yet unquantified--degree. Yet all we seem to have to argue over is a (valid) theoretical conclusion that induction is 10+% more efficient than cooktops that get hot all by themselves. You know the tripe: "That would defeat the purpose of *having* induction!"

                      I have mused in the past that this theoretical platitude is not a real answer, and that perhaps when induction *and cookware* (all, not just ferritic) are considered and *actually tested* in an integrated way, we just may find some surprises in terms of practical real-world efficiencies.

                      Your tests with Prima Matera have already stepped boldly in that direction. This is important work, and no one else is doing it! I applaud you for that (and especially for sweating the emissivity detail), and so I hope that you might rethink working a converter disk into your future experiments.

                      I would be just as happy to be proven wrong in my theories as right, but we need proof.

                      Aloha Aikane,
                      Kaleo

              2. re: tanuki soup
                Chemicalkinetics Oct 4, 2011 08:44 PM

                Somehow I missed this post, but evidently I did. These are great results. Although I am not really surprised. I think the idea that copper and aluminum pans have better heat distribution than others. I am also not surprised that carbon steel and enameled cast iron behave worse. What surprise me is that tilt his day people til argue cast iron cookware have extremely even heating surface. That does not make sense based on your data, and it never made sense based on basic knowledge.

                Now, the edge of a pan being cooler is inevitable. I mentioned this in a separate post that that the edge is very much like a boundary condition

                http://chowhound.chow.com/topics/8086...

                There is no way for a pan's edge to be the same tempeature of the pan center. Think about it. The center of the pan has direct heat transfer, where the edge of the pan relies on a rather long distance to transfer that heat and it has great heat loss from the curved edge. So why would they be in the same temperature?

              3. tanuki soup Aug 31, 2011 03:10 AM

                Due to the surprisingly low temperature readings for the de Buyer Prima Matera pan, I decided to repeat the measurements for this pan at a higher temperature setting of 4 rather than the standard setting of 3 that I used for all the pans in the initial tests.

                As I was doing the repeat test, I noticed that the readings displayed by the IR thermometer seemed to be lower than the actual temperature of the pan. For example, even though the thermometer would read, say, 75C, water splashed into the pan would sizzle and bead up, clearly indicating that the true temperature was higher than 100C.

                So I stopped the test and put a small amount of safflower oil into the pan and read the temperature of the oil with the IR thermometer. The reading was much higher than the reading for the adjacent bare metal. I guess the reflectivity of the stainless steel interior screwed up the IR thermometer's readings.

                I apologize for blindly accepting the readings of a cool high-tech gadget.

                In any case, I have repeated the measurements for the de Buyer Prima Matera pan at the original temperature setting of 3 that was used for the first round of measurements. The only difference is that I wiped a thin layer of safflower oil over the entire inner surface of the pan before starting the test.

                The graph is shown below.

                The temperature readings are significantly higher at each time point. However, the PM pan still shows the most even temperature distribution from center to edge, so I guess it retains its crown.

                Once again, I apologize for posting inaccurate data in my earlier post.

                Tanuki Soup

                 
                15 Replies
                1. re: tanuki soup
                  c
                  careme_fan Sep 1, 2011 10:47 AM

                  Thanks TS, great experiment! The new graph looks more plausible, although I am not entirely convinced that the temp is not even higher. The reason is as follows: assuming that all pans are getting the same amount of energy from the induction knob (which might not be entirely true) the temperature should be dependent of their mass * thermal capacity. The thermal capacity of copper is 0.385 J•g−1•K−1 while stainless steel is 0.510. (See http://www.diracdelta.co.uk/science/source/s/p/specific%20heat%20capacity/source.html) So an equal weigh stainless steel pan would heat about 30% slower. (You need 385 J to heat 1 Kg of copper 1 degree, vs 510 for stainless steel) Of course this ignores heat loss, the weight of the handle, etc But I am surprised that the Silit appear to heat faster because the heat loss of the PM does not appear to be very high -- it actually cools very slowly.

                  What IR thermometer are you using? If the emissivity is not adjustable it is probably set at 0.95 . Clean stainless steel has emissivity just 0.075 (http://www.engineeringtoolbox.com/emi... ). I have no idea what oiled SS does, but probably is not 0.95 so you are underestimate the temp. I am very far from an expert, so I do not know how to adjust the reading if you do not have a built in adjuster. Hmm, maybe I'll buy an IR thermometer myself and try it on my more modest pan collection :-)

                  1. re: careme_fan
                    tanuki soup Sep 2, 2011 02:14 AM

                    Thanks for the detailed response, careme_fan:

                    You've raised a lot of interesting points. Unfortunately, some of them flew right over my head!

                    1) The non-contact IR thermometer:

                    The unit I have is just an inexpensive (less than $100) pistol-type non-contact IR thermometer with a laser pointer, ordered from Amazon Japan. I don't believe it has any sophisticated adjustment or calibration functions. When I first got it, I did a number of informal tests. It seemed to be pretty accurate reading ice cubes in the freezer (-19C), a stainless steel kettle on the boil (95C), a cast iron pan with extra virgin olive oil just at its smoke point (220C), the inside of my mouth - really! (36.5C), and so on. In addition, during the experiments described in my original post, all of the pans read 28C at all three measurement points before the heat was turned on (0 min). This agreed with the room temperature displayed on a digital thermometer hanging on the wall of my kitchen.

                    The thing that I find most surprising is that the IR thermometer had no difficulty reading the temperature of the Prima Matera frying pan at room temperature. It read 28C at the center, halfway out, and at the edge, just like all the other pans. Why should the thermometer accurately read the temperature of the PM pan when it was at room temperature, but not when it was heated up on the induction cooktop?

                    Maybe a quick-and-dirty way to assess the accuracy of the temperature measurements would be to start heating up each pan and check the reading displayed on the thermometer when water droplets splashed into the pan start to bubble and sizzle.

                    2) Induction heating

                    I have to confess that I have only the most basic understanding of induction heating. As I understand it, a coil underneath the glass surface generates an oscillating magnetic field that induces eddy currents in a magnetic pot placed on the cooktop. The eddy currents in the pot cause it to heat up. The thing that makes induction cooking unique is that external heat is not applied to the pan; instead, the heat is generated within the pan itself.

                    As for the specific factors that might influence the speed or efficiency of induction heating, I really have no idea.

                    Let's say you have an aluminum pan with a 2-mm-thick magnetic base stuck on the bottom to make it induction-capable and you have an identical aluminum pan with a 4-mm-thick base. Which one would heat up faster? On one hand, you could argue that the pan with the thinner magnetic base would heat up faster because there is less total mass to heat up. On the other hand, you could argue that the pan with the thicker base would heat up faster because there is more magnetic material to conduct the eddy currents and thus generate heat.

                    If the latter argument is correct, I figure that the Silit Silargan (stainless steel), carbon steel, and cast iron pans heated up more quickly because the entire pan is made of magnetic material.

                    Another point is that the mechanism for heating up the pan (internal heat generation) is totally different from the mechanism for cooling down the pan (transfer of heat to the external environment).

                    Also, as you briefly mentioned, the magnetic material conducting the eddy currents wasn't the same for all the pans: stainless steel, carbon steel, cast iron, and unidentified magnetic disk bottoms on the aluminum and copper pans. These materials may couple to the oscillating magnetic field with greater or lesser efficiency.

                    Finally, does the induction cooktop itself somehow monitor and regulate the heating of the pan? It certainly senses whether or not a pan is placed on it, since it turns off when the pan is lifted. My particular unit also has direct temperature control (you can set it to heat the pan to a specific temperature such as 160C). Does the temperature setting of the cooktop (I used the "3" setting in these tests) simply indicate the amount of power supplied the induction coil, or is some sort of feedback regulation system used?

                    There really are a huge number of factors to consider. It would be great if you could run your own experiments so that we could compare findings. Also, it would be interesting to see results for other types of cooktops (gas, electric, halogen, etc.).

                    Thanks again for your reply,

                    Tanuki Soup

                    1. re: tanuki soup
                      d
                      Dave5440 Sep 2, 2011 04:33 AM

                      Great topic TS, and I think the answers will reveal themselves. I do have a question about your IR unit , did it specify what spot ratio it is? And were you holding it at a 90deg angle to the surface at the distance the ratio would give you the correct segment temp. Also it occured to me if you were holding the IR meter correctly the rising heat of the pan could skew the results from the meter electronics heating up

                      1. re: Dave5440
                        tanuki soup Sep 2, 2011 05:01 AM

                        Hi, Dave5440:

                        According to the manufacturer of the IR thermometer, the effective measurement "window" ratio is 12:1 (i.e., it reads a 1-cm circle at a distance of 12 cm).

                        I tried to keep the thermometer at a constant distance of about 25 cm from the pan surface, corresponding to a measurement spot about 2 cm in diameter. I also held the thermometer vertically for the measurements at the center of the pan and halfway out from the center, and at right angles to the inner wall of the pan (just eyeballed it) for the measurements at an inch in from the edge.

                        The thermometer seemed to take readings almost instantly, so I didn't have to hold it over the pan for too long. Neither the unit nor my hand became uncomfortably hot during the process.

                        Actually, given the problems I encountered in trying to measure the temperature of the Prima Matera pan, I wonder whether using some sort of quick-reading physical-contact probe thermometer might give more accurate results than my non-contact IR thermometer.

                        1. re: tanuki soup
                          d
                          Dave5440 Sep 2, 2011 05:39 AM

                          I would tend to agree with you on using a contact thermocouple, I am kind of suprised that a sub 100$ ir gun has a 12:1 ratio. my "cheap" one i bought in canada with a 3:1 was 150$ and every single gun i've looked at is in imperial measurement not metric so your measurement area could be off by the difference

                          1. re: Dave5440
                            tanuki soup Sep 2, 2011 06:27 AM

                            Well, since I live in Japan, I ordered my IR thermometer from Amazon Japan for a bit more than 5000 yen (US$65). It's a Japanese unit, and definitely metric. Here's a pic of the information from the manufacturer. Although it's in Japanese, the diagram clearly shows that the measurement distance to measurement area diameter ratio is 12:1. How optimistic this specification may be is another matter ;-)

                             
                            1. re: tanuki soup
                              d
                              Dave5440 Sep 2, 2011 07:30 PM

                              No arguing that it's 12:1 alright, that should convert to 10:1 for imperial, wow for 65$ I could get it shipped here and be up 50$

                      2. re: tanuki soup
                        c
                        careme_fan Sep 3, 2011 01:56 AM

                        Dave5440:

                        You can buy a IR gun with 12:1 optics + adjustable emissivity for just $49 + $6 shipping from Thermoworks, the sellers of Thermapen. (I have a Thermapen and it is excellent!) See http://www.thermoworks.com/products/i...

                        BTW, their web site says the following:

                        "Emissivity em·is·siv·i·ty n.

                        The ratio of the radiation emitted by a surface to the radiation emitted by a blackbody at the same temperature. It is therefore a measure of a material’s ability to emit infrared energy. Materials are assigned an emissivity value between 0 and 1.0. Most organic materials such as paints, plastics, fabrics and food have an emissivity value near 0.95. Low cost IR meters typically have a factory fixed emissivity setting of 0.95. The emissivity value of bare metals is considerably lower and so they should be measured with an IR meter that offers adjustable emissivity."

                        HTH, -- CF

                        1. re: careme_fan
                          tanuki soup Sep 3, 2011 03:37 AM

                          Thanks for the great info, CF.

                          I also have a Thermapen, and love it. Thermoworks is a really good company. I would have absolutely no hesitation ordering an IR thermometer from them. (They are happy to ship worldwide.) I wonder if they still put a little bag of jelly beans in the box? A charming touch.

                          BTW, if the emissivity setting of my IR thermometer is (presumably) 0.95 and the actual emissivity of stainless steel is 0.75, would it be possible to simply multiply my original readings by a correction factor of 0.95/0.75 (= 1.27)? If so, would the correction factor be applied to the temperature in kelvin rather than centigrade?

                          Also, I still find it difficult to understand why the stainless steel interior of the Prima Matera pan gave accurate readings at room temperature, but not on the cooktop.

                          Thanks again for sharing your expertise, CF.

                          1. re: tanuki soup
                            c
                            careme_fan Sep 3, 2011 05:05 AM

                            Sorry TS, sad to say, I am far from being an expert. However I don't think that you can simply apply a linear correction but you can calibrate the emissivity to make the IR reading match a thermocouple reading. The whole story is quite complex -- you might want to read a short intro at "Principles of Infrared
                            Thermometry" http://www.omega.com/temperature/Z/pd... but I must confess I do not completely understand it. I wish a real expert would chime in.

                            But back to playing with pans: at least at low temp (say up to 75 c) I guess you can just put a piece of black electrical tape on the pan and read off the tape. At higher temps the tape will melt and make a mess -- you might not want to risk this with your nice new pan!!

                            Thanks for the experiments again! -- CF

                            1. re: careme_fan
                              d
                              Dave5440 Sep 5, 2011 07:51 AM

                              Thanks for the information, That would explain a few things about my gun

                          2. re: careme_fan
                            tanuki soup Sep 6, 2011 02:43 AM

                            Thanks again, CF:

                            I ordered the IR gun you recommended from the nice folks at Thermoworks last night. I plan to repeat the measurements for the Prima Matera pan with the emissivity set to 0.12 or 0.14 (which is the typical value given for machined stainless steel -- the inside of the PM pan isn't mirror finished, but has tiny concentric ridges).

                            BTW, I found another great article about the use of IR thermometers at the Fluke website. Not as technical as the one you kindly posted, but a really clear explanation of the various factors and pitfalls in practical applications. In particular, it explains why the Prima Matera pan gave reasonable-looking readings at room temperature, but not on the cooktop. If you're interested, here's the link:

                            http://support.fluke.com/educators/Download/Asset/2563251_6251_ENG_B_W.PDF

                            Also, here's a link to a very complete list of emissivity values for various materials:

                            http://www.electro-optical.com/eoi_pa...

                            Best regards,

                            TS

                            1. re: tanuki soup
                              k
                              kaleokahu Sep 6, 2011 07:52 AM

                              Hi, tanuki soup:

                              Just caught up a bit here... Good on you for doing this and going to such great lengths to be accurate. Personally, I don't think the emissivity adjustments are going to affect how closely grouped the edge/midway/center lines are, but the slope shapes could change.

                              Once you get this dialed in, I suggest you repeat the tests on a variety of hobs--gas, resistive coil, radiant, etc. The energy settings would be difficult to replicate, but I think it would nevertheless be worthwhile.

                              Thanks again for your work,
                              Aloha,
                              Kaleo

                              1. re: kaleokahu
                                tanuki soup Sep 7, 2011 01:47 AM

                                Hi, Kaleo:

                                I plan to repeat the measurements only for the Prima Matera pan (at an emissivity setting of 0.14), so it should only take 15 minutes or so. I checked the emissivity of the other materials, and they all seemed to be around 0.90 or 0.95, so I figure the original measurements should be okay.

                                BTW, I also read at a professional kitchen site somewhere on the Interwebs that applying a thin coating of oil to stainless steel is a good way to improve IR temperature measurements, so hopefully the second set of curves for the PM pan (with safflower oil) shouldn't be too far off.

                                Like you, I expect that the curves for the Prima Matera pan will still be closely grouped in the repeat test, but that the temperature will rise more quickly to a higher peak and and then fall off more rapidly. It was pretty obvious just from handling the pan during and after the earlier tests that it had heated up very evenly out to the edges, with no apparent hot spots.

                                TS

                                1. re: tanuki soup
                                  k
                                  kaleokahu Sep 7, 2011 03:27 PM

                                  Hi, tanuki:

                                  Let me know if, in your research, you come across an emissivity figure for tin.

                                  Also, you should run that sexy Japanese cast iron skillet of yours in this race, too.

                                  Cheers,
                                  Kaleo

                    2. tanuki soup Aug 31, 2011 01:37 AM

                      Oops!

                      1. c
                        cutipie721 Aug 30, 2011 10:08 AM

                        That's some beautiful data, thanks TS!! In terms of evenness, looks like nobody beats copper. I am very disappointed to see how slowly it heats up.

                        1. tanuki soup Aug 30, 2011 05:46 AM

                          Hi, guys.

                          Got psyched up tonight and ran the tests.

                          The graphs showing the results are arranged in the following order.

                          (1) de Buyer Prima Matera (induction-capable copper)
                          (2) Archetun (induction-capable aluminum, nonstick)
                          (3) Silit Silargan (stainless steel with ceramic coating)
                          (4) TKG Pro (carbon steel)
                          (5) Mario Batali (enameled cast iron)

                          The way I look at it, the closer the lines are to each other on the graphs, the better, since it means that the temperatures measured at the center, halfway out from the center, and at the edge of the pan at each time point are nearly the same.

                          It's probably no surprise to anyone (especially Kaleokahu) that the de Buyer Prima Matera induction-capable copper pan left all the other contenders in the dust. The lines are amazingly close to each other throughout the entire heating/cooling cycle. One thing that did surprise me was how slowly the pan heated up and cooled down. The peak temperature was only one-third to one-half that reached by the other pans. I suspect that this was because the entire pan was absorbing and spreading the heat -- and there is a LOT more metal at the edges of a pan than at the center

                          The Archetun pan (induction-capable aluminum) finished a distant second, followed by the Silit Silargan pan (stainless steel/ceramic), and then the carbon steel and cast iron pans, which seemed to show pretty similar characteristics.

                          I hope you guys find these results interesting.

                          Tanuki Soup

                           
                           
                           
                           
                           
                          7 Replies
                          1. re: tanuki soup
                            e
                            ellabee Aug 30, 2011 08:44 AM

                            Thanks so much, ts! These are _very_ interesting.

                            Now it would be wonderful for someone with extra $$ to do a similar experiment with 4-qt Dutch ovens on induction -- including the new Tramontina 100th anniversary Lyon line (thick, non-cast aluminum with nonstick surface) and the deBuyer Prima Matera stew pot along with enameled cast iron and a few other alternatives.

                            1. re: tanuki soup
                              k
                              kaleokahu Aug 30, 2011 08:50 AM

                              Hi, tanuki:

                              Wow, nice job! Even *I* was amazed at the huge temperature differences in the iron and steel pans.

                              My interpretation of the results is that (a) the Prima Matera pan on induction delivers extremely even heat; and (b) the "slowness" you observed is attributable to the thick bottom disk and (on the way down) the ceran smoothtop. So I think deBuyer has completely solved the evenness problem. Responsiveness less so.

                              It would be interesting to repeat your test with a converter disk and straight copper pan. My bet is you would have substantially similar results IF you put the cold disk and the cold pan on the induction hob. But I think if you started with the disk already in place and at heat and THEN put the pan on, your graph would look like the Matterhorn on the way up (To get good downward responsiveness, you'd need to re/move the pan).

                              Interestingly, I wonder how the results might have been different if the Prima Matera pan only had one of the new spray-on magnetic bottoms. I dislike this idea from a durability aspect, but it would also seem to better the pan's responsiveness on induction.

                              Thanks again for your efforts... Keep up the good work.

                              Aloha,
                              Kaleo

                              1. re: kaleokahu
                                i
                                INDIANRIVERFL Aug 30, 2011 08:59 AM

                                But which one is best at frying an egg?

                                1. re: INDIANRIVERFL
                                  k
                                  kaleokahu Aug 30, 2011 09:13 AM

                                  Hi, INDIANRIVERFL:

                                  One egg fried in the center of the pan? Not a lot of difference. An omlette on the other hand...

                                  Aloha,
                                  Kaleo

                              2. re: tanuki soup
                                m
                                mateo21 Aug 30, 2011 10:10 AM

                                mmmm... data...

                                Thanks for running these, Tanuki! Awesome info.

                                I've been thinking for a while about doing something like this with SS vs. Tin copper pans. My method was going to be a bit more complex using copper shot and a calorimeter... hmmm... now to get my hands on a tinned copper pan.

                                1. re: tanuki soup
                                  c
                                  careme_fan Aug 30, 2011 03:05 PM

                                  Wow! Amazing graphs -- thanks Tanuki Soup. I wonder however about the responsiveness of Prima Matera -- can you do another test and heat it up to say 150C? The graph might be less symmetric. The flat temp is amazing, but if the pan takes forever to cool, I am not sure what exactly would you cook in it. THANKS! -- CF

                                  1. re: tanuki soup
                                    cowboyardee Sep 3, 2011 05:17 AM

                                    Very cool, tanuki. Thanks.

                                  2. s
                                    skyline Aug 29, 2011 01:18 PM

                                    I would be interested too, because I just ordered the Silit and still haven't decided whether an induction or an electric cooktop will be going into the next kitchen. And since the Silit is the priciest of the frypans that I have, and I have a feeling will be the one I'll be using most often from now on, I'm really curious to know how it behaves on an induction.

                                    I like Kaleo's Suggestion #4 a lot too (the butter test).

                                    1. k
                                      kaleokahu Aug 29, 2011 08:51 AM

                                      Hi, Tanuki:

                                      AbsoLUTEly I'm interested!

                                      Suggestions: (1) Do your measurements every minute on the "down" side, too.
                                      (2) Also do the flour "scorchprint" test for each pan. (3) If you have access to a straight 3mm copper pan and a converter disk, add that combo into the mix. (4) Run a test with just butter in the pans to test when and where the butter darkens.

                                      REALLY interested in what you think of the Prima Matera.

                                      Aloha,
                                      Kaleo

                                      1 Reply
                                      1. re: kaleokahu
                                        tanuki soup Aug 30, 2011 01:35 AM

                                        Thanks for the advice, Kaleo. I'll take measurements every minute both "up" and "down".

                                        As for the flour and butter tests, I think I may hold off for a while. If I just use the IR thermometer, I won't have to wash a bunch of frying pans after conducting the experiments!

                                        BTW, the attached image shows the way I'm thinking to display the results. What do you think?

                                         
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