Induction-Friendly Cookware Selection

[adrianvm]

Most of my measurements were of a nonstick pan, not stainless.   When I did measure stainless I put oil in the pan so I was measuring oil rather than metal.   Any advice on buying a thermocouple I can tape to the pan without spending a lot?  And type of tape to use?   (The thermocouples I have are for sous vide, pointy probe shape tips.) 

 

Note that now that I understand how things work the thing that is bothering me is that the steady state temperatures I'm getting are higher than the set point by 20-40 deg depending on the pan.   And yes, this doesn't make sense thermodynamically, so it suggests that either the Freak is misreading the temperature or my thermometers are.  It seems important to figure out which one. 

 

On this very thread people have been suggesting the Analon copper pans.  These are advertised to have a layer of copper in the base that spreads the heat and visibly appear like they have a quite thick layer.  But Analon (like almost every other pan manufacturer, I'll note) says nothing about how thick any of the layers are, and the pans are cheap at $70 for a set of two skillets.  I asked them and have not heard back.   This is not uncommon, though.  The pan companies tell you how many layers there are but not how thick anything is, like Demeyere is supposed to be great because it has 7 layers!  Maybe it'll be even better next year when the 9 layer version comes out!   I asked another vendor about their pan thickness and they didn't know but did eventually get the information---it took a week.  

 

Wouldn't cast iron be uneven on every heat source?

 

The Freak manual says minimum pan size is 5.5 inches.  Why do you think it is actually 6.3"?   What goes wrong if the pan is smaller than 6.3 inches? 

[Laurentius]

3 hours ago, adrianvm said:

  What goes wrong if the pan is smaller than 6.3 inches? 

 

The pan detection doesn't work properly/dependably.

[adrianvm]

43 minutes ago, Laurentius said:

 

The pan detection doesn't work properly/dependably.

 

So even though the manual says 5.5" the pan detection won't reliably detect a pan at that diameter?  I haven't noticed problems with pan detecting using my All-Clad windsor pan, which has a base of about 5.75 inches.   Could this behavior be different between the original Freak and the Home version?

[MJS301]

I have a cheap pan from Amazon I use solely for low heat work, eggs etc on my CF commercial. It's 15cm (5.9") base & the CF has no problem detecting it.

[Laurentius]

7 hours ago, adrianvm said:

 

So even though the manual says 5.5" the pan detection won't reliably detect a pan at that diameter?  I haven't noticed problems with pan detecting using my All-Clad windsor pan, which has a base of about 5.75 inches.   Could this behavior be different between the original Freak and the Home version?

It depends on the pan and the appliance. This (detection) is a general issue with induction, and it's difficult to predict--and easy to dispute--if your particular pan works on your particular appliance.

 

The appliance makers don't test every conceivable small pan.  The generalize.

[adrianvm]

The manual does say "Cookware smaller than 5.5"/14cm may not work (material dependent)".  So it seems like it's not a clear cut hard boundary.  Can anybody identify a 6" pan that fails?  That is, what sorts of pans are harder to detect?  Or very small pans that work fine? 

[adrianvm]

Regarding the Analon copper that has been mentioned several times here as a good nonstick option, I wrote to Analon to ask about the construction and got this reply:  "While we appreciate your interest in the construction of our cookware, we regret to inform you that specific details regarding the thickness of the stainless steel, aluminum, and copper layers are proprietary information and cannot be disclosed."  I would assume this means that they have something to hide about the construction.

[palo]

1 hour ago, adrianvm said:

I would assume this means that they have something to hide about the construction.
 

But from whom?

 

The consumer or their competitors?

 

p

[Dex]

13 minutes ago, palo said:

But from whom?

 

The consumer or their competitors?

 

p

Who is less likely to take a band-saw to a pan?

[Laurentius]

30 minutes ago, Dex said:

Who is less likely to take a band-saw to a pan?

Having sawn a few pans myself, and having worked in cookware development, I can tell you that many makers treat even their thickness specs like nuclear launch codes.  They keep them from even their own sales and marketing people.  They do so even when told a pan will just be destructively tested.

 

After years of this tomfoolery, I've concluded they just are doing everything they can to minimize potentially unfavorable comparisons.  It's assinine.

 

The true secrets are in how the pan is put together, not how thick it is or (generally) what's in it.

[afs]

On 5/2/2024 at 6:27 AM, adrianvm said:

Most of my measurements were of a nonstick pan, not stainless.   When I did measure stainless I put oil in the pan so I was measuring oil rather than metal.   Any advice on buying a thermocouple I can tape to the pan without spending a lot?  And type of tape to use?   (The thermocouples I have are for sous vide, pointy probe shape tips.) 

 

Unfortunately I don't have any recommendations on affordable thermistors/themocouples.  Kapton tape usually works splendidly.

 

On 5/2/2024 at 6:27 AM, adrianvm said:

Wouldn't cast iron be uneven on every heat source?

 

Some heat sources (like old wood stoves and continuous induction cooktops) can provide pretty even heat for cast iron pans.  But more to the point, induction in particular directs the heat directly into the pan--and so issues with hot spots on cast iron are exacerbated with induction.  They're really just not a great match on single-coil induction cooktops, generally speaking.

 

On 5/2/2024 at 6:27 AM, adrianvm said:

The Freak manual says minimum pan size is 5.5 inches.  Why do you think it is actually 6.3"?   What goes wrong if the pan is smaller than 6.3 inches? 

 

Sorry, I should have been more clear and I should have double-checked the specifications.  I use pans down to 14cm (5.5") and the current Control Freak manual actually says that it will handle pans all the way down to 12cm (4.5").  The specs on the size range have actually changed over time (i.e. the original Control Freak manuals quoted a pan diameter wider than 10"), but then again they may have previously been measuring the colloquially-quoted (top) diameter rather than the pan surface (bottom) diameter.  Your pans with a 5.5" base should work fine if the instruction manual says 5.5 inches minimum.  Just be sure to put the pan in the center of the surface; the smaller that pans get, the more critical it is to center the pans.  Also please be aware that smaller pans may not be able to handle the full ~1700W of power without resonating, so you may need to heat the smallest pans on a slower setting.

[adrianvm]

I've noticed this problem with the sales staff not knowing the pan thickness.  I asked one brand and the sales staff measured the pan thickness themselves and gave me a number.  But they don't know how thick the aluminum portion is.  I asked another brand and they didn't know, but they were able to get the information from "the engineers" in about a week.  I think the explanation for the secrecy has got to be the one given by Laurentius: they just are doing everything they can to minimize potentially unfavorable comparisons.  The less actual information we have the harder it is to make meaningful comparisons, which might be unfavorable. 

 

The manual for the Control Freak Home is somewhat vague about what they mean by pan size with the 5.5" value.  The little diagram shows a pan being measured at the top, but it is a pan with vertical sides.  Of course, even many straight sided pans have a smaller base then their top diameter. 

 

When I tried to do temperature measurements with my very tippy All-Clad windsor nearly empty, the pan was so off-center that I got sporadic messages that the pan was not on the temperature sensor.  But it always seemed to actually detect the pan.  Of course, operating this way is clearly not ideal---better for the Freak to measure the temperature in the center of the pan---but it seemed to work. 

[adrianvm]

@afsYou mentioned earlier using Falk and Demeyere on your CF.  I was looking at sauciers and wondering, for a pan like this, whether the difference between the 5 layer and 7 layer pan is noticeable at all.  Or how those pans compare to the Falk with copper instead of aluminum.   From what I can tell, the only difference between the 5 layer and 7 layer pans (Atlantis and Industry 5) is that the Atlantis has the magical "triplinduc" layer on the bottom and the Industry 5 just has stainless steel.  Otherwise they have the same construction with apparently the same amount of aluminum. 

[adrianvm]

Analon Copper which has been recommended a bunch is also quite concave on the bottom.  What nonstick pans are not concave? 

[afs]

6 hours ago, adrianvm said:

@afsYou mentioned earlier using Falk and Demeyere on your CF.  I was looking at sauciers and wondering, for a pan like this, whether the difference between the 5 layer and 7 layer pan is noticeable at all.  Or how those pans compare to the Falk with copper instead of aluminum.   From what I can tell, the only difference between the 5 layer and 7 layer pans (Atlantis and Industry 5) is that the Atlantis has the magical "triplinduc" layer on the bottom and the Industry 5 just has stainless steel.  Otherwise they have the same construction with apparently the same amount of aluminum. 

I have some Industry 5 pans in storage somewhere...  If I remember correctly, the Proline pans were actually better at spreading around the heat. 

Note that the Proline and Atlantis lines have largely been merged together, with the Proline pans being the stainless-clad aluminum pans and the Atlantis being the copper disc-bottom pans with stainless exterior (if I remember correctly).  They make a pretty reasonable cohesive lineup together.

I typically stick with 3-layer (thin stainless steel covering layers on the inside and outside, with a thick layer of aluminum or copper in the middle).  The 5-layer and 7-layer pans, if they're alternating between aluminum and other materials, tend to react less quickly and be more forgiving for cooks who don't have sophisticated cooktops with temperature control.  But for the Control Freaks, I haven't found any advantage to using "more layer" pans yet.  That said, the Demeyere pans might have a multi-layer construction on the bottom that is used to capture heat via induction while providing an easier to clean surface--and that is a different edge-layering approach which is really more about conduction than about spreading heat around the pan.

Finally, as far as the Control Freak (and Control Freak Home) manuals, I believe that the dimensional figures are meant to show the minimum and maximum sizes specified for the bottom of pans--which is why they're showing pans with straight sides.  There is so much confusing terminology around pans, and I think they're trying to simplify it all down in a simple drawing.  In any case, I would generally not recommend any saucier or frying pan-shaped pans (i.e. with large curvature) below 18cm or above 28cm.  And I would not recommend any straight-edge pans smaller than 14cm or larger than 26cm (although I do use 28cm saute pans, I recognize that the edges aren't getting direct heat and I adjust accordingly when necessary).

[adrianvm]

The business of counting layers is kind of silly.  What matters is what the layers are.  I never understood why All Clad was sticking extra stainless steel layers into their pans.  But that's not what Demeyere does.   They seem to be counting "layers" that are just junction materials between the main pan materials---layers that presumably are of negligible thickness.  It's marketing. 

 

You have to be careful when comparing Proline/Atlantis to Industry 5.   My understanding is as follows.  Proline skillets are 4.8mm thick.  Industry 5 skillets are 3mm thick.  Clearly Proline will be better.    But other clad pieces are the same thickness (3mm) in both Atlantis and Industry 5 lines, so for the sauciers I'm looking at, both Atlantis and Industry 5 are 3mm thick. 

 

It's a bit of a contradiction to say that more layers isn't better but then that you prefer proline, which is "7 layers".  So what are these 7 layers?  They are "triplinduc" then pure aluminum, aluminum alloy, pure aluminum, stainless.  The aluminum alloy is supposedly more heat conductive than pure aluminum.   The "triplinduc" is three layers of stainless steel that is supposedly "30% more efficient" on induction than other materials.   The disk base Atlantis pans also have "7 layers" which are triplinduc, silver, copper, silver, stainless.  Somehow I doubt those silver layers are more than a few microns thick, but they can't hurt pan performance since silver has better conductivity than copper. 

 

So getting back to the question of whether it's worth paying more for the Demeyere Atlantis saucier vs the Industry 5 saucier, it appears that the difference between the two products lies entirely in the mysterious "triplinduc" material, which is used in the Atlantis but not the Industry 5.  Those are the "layers" you lose.  So is this special induction material actually delivering some detectable advantage?   They claim that it's more magnetic and has more resistance to deformation. 

 

In terms of special materials Demeyere also has an intriguing material they call Controlinduc that is designed to prevent overheating of the pan.  Not of practical interest to Freak owners, but I thought it was interesting:  as the pan heats past a threshold (225C) the base begins to lose its magnetic properties, so the induction cooker cannot heat it hotter than about 250C.  

 

I would imagine that Falk should be better than the Atlantis clad pans because it has almost as much copper as the Atlantis and industry 5 pans have aluminum.  But the Falk is quite a bit more expensive, I think more than double in some cases. 

 

 

 

[Laurentius]

9 hours ago, adrianvm said:

I never understood why All Clad was sticking extra stainless steel layers into their pans. 

 

They were ginning up a reason for another line, d5 (and the "Thomas Keller").  The underlying theory was Start-Stop-Start, i.e., that, by interweaving SS with aluminum in thin layers, heat was "forced" outward through the aluminum, allegedly resulting in more even heating.  The theory makes no sense.

 

A-C even offered a few pieces of d7 with even more pointless steel.  They tried justifying that by claiming it made the pan just like cast iron (!!!), only lighter.

 

Go figure.

[Laurentius]

10 hours ago, adrianvm said:

Demeyere also has an intriguing material they call Controlinduc that is designed to prevent overheating of the pan.  Not of practical interest to Freak owners

Unless someone cooks ONLY on a Control Freak (and never above about 300F), ControlInduc is a very practical feature.  Fire and lung safety is but one advantage.  

 

The pan employs a magnetic alloy whose Cutie point is the cutoff temperature, but it is a gradual tailing off.  God Knows what might happen if/when it stifles the Gf's button sensor.

[adrianvm]

I tested 3 pans using a pair of thermocouples, one that I tried to place in the pan center and one that I placed at the pan edge.  I tried an off-brand of Kapton tape but it let go very quickly as the pan heated.  A very large piece of blue painter's tape worked OK to hold the thermocouples in place.   All tests were to 250 F on low intensity with an empty pan. 

 

The first pan was the 8.5" Heston nonstick skillet.  This is a clad pan with a concave bottom (1mm concavity).   When the pan temperature was stable and the CF was reporting 250 measurements at the pan center ranged from 236-238.  Measurements at the pan edge ranged from 243-246.   IR thermometer measurements towards the edge were 272-276. 

 

The second pan was the Analon Copper, 10 inch fry pan.  This pan has a flat disk base that allegedly contains copper.  The base is concave by a similar amount as the Hestan, about 1.1mm.  With this pan the center measurements ranged from 246-250.  I did have one low measurement at 243.  The edge measurements (still over the disk base) ranged from 243-245.  The IR thermometer reported 268-276.

 

The third pan was a Demeyere Atlantis dutch oven with a 9 inch base diameter.  This is the thick base style pan that has 2mm copper in the base.  This pan is something like 15-20 years old. The bottom of the pan is somewhat warped, but convex, not concave.  It's hard to estimate the size of a convexity, but maybe it's around 0.3mm.  With this pan, the center measurement was between 248-253.  The edge measurement was 241-245.  For completeness I tried the IR thermometer on this pan and it read 115.  (A bad reading is expected due to the stainless steel cooking surface.) 

 

In all cases when the pans were heating up the pan center seemed to outpace the sensor, reading ~8 deg F warmer than the sensor was reporting.

 

So it seems like the CF is most likely working correctly.  The big discrepancies I observed before in steady state temperature were IR thermometer readings and they seem to be high. 

 

I'm not sure what to make of the Heston pan performance.  One of the questions is whether to return that pan.  Why is the pan temperature lower than the CF setting?  How can this happen?  That implies that the CF is reading a hotter temperature than the pan actually is.  Or that the pan is 12-14 degrees F colder at the top surface than the bottom in steady state. 

 

Another observation is that the Analon seems to do OK in this test despite its concave bottom.   Finding pans that are not concave seems to be somewhat difficult. 

[Laurentius]

14 hours ago, adrianvm said:

In all cases when the pans were heating up the pan center seemed to outpace the sensor, reading ~8 deg F warmer than the sensor was reporting.

 

I am unsurprised.  Nearly everyone who buys a CF does so believing it's absolutely correct, constant and precise.  Good luck convincing them otherwise.  The spring-loaded button thermocouple is good, but it's not that good, and the thermal contact isn't that great.

 

Just for fun, you might try a dab of thermal grease on the button to improve contact, and compare.

 

Also, the button is in the center, not above the coil.  The field falls off rapidly with distance, too, so you have both less heat being applied dead center AND you have heat piling up there in an empty pan (Visualize the heat moving both inward and outward from the coil--this happens with gas and electric, too).  Add in all the variables of pan construction, and it's... imprecise.

[Dex]

1 hour ago, Laurentius said:

 

Just for fun, you might try a dab of thermal grease on the button to improve contact, and compare.

 

 

I thought about using a high-temp thermal pad. It will tighten the hysteresis loop. But it's ultimately going to be limited by the conduction of the pan between the inner induction ring and the sensor, probably too much trouble for the benefit.

[adrianvm]

Yeah, I'm not shocked that the pan center outpaced center readings as the pan was heating. 

 

But I am puzzled that for one pan, steady state has the Freak measured temperature 15-20 degrees higher than the thermocouple measured temperature at the pan center, above the Freak sensor.   Does that mean the top surface of the pan is 15-20 deg below the bottom in steady state?   Sensor readings should not be **higher** than actual temperature due to any sort of coupling issue.   So is there a temperature gradient vertically across the pan thickness and if so, why is it larger for the Hestan pan and smaller for the Analon and Demeyere pans?   Is something wrong with the Hestan?  And if so, what?  Note that the Hestan pan is 3mm thick which might mean it has the thinnest base of the three pans.    

 

 

 

[Laurentius]

2 hours ago, adrianvm said:

the Hestan pan is 3mm thick which might mean it has the thinnest base of the three pans.    

Which Hestan is this?  My understanding is that Thermoclad is 2mm of aluminum, and the Nanobond is a bit thinner.  They allege the cores are pure aluminum for "up to 35%" better conductivity.  I've had a Thermoclad, and I see no difference.

[adrianvm]

It's the Thomas Keller Insignia Titium nonstick 8.5" skillet.  I think it's the same as the probond titium nonstick.  I am not sure where I got the 3mm thickness number from---they don't advertise it on their site.  I think maybe it was a reddit post that says: "FWIW I asked Hestan directly and was told the frying pans are 3mm, and everything else is 2.3mm. This lines up with what I saw in the store."  I think that's total thickness, not aluminum thickness. 

[dtremit]

On 5/5/2024 at 12:48 PM, adrianvm said:

Yeah, I'm not shocked that the pan center outpaced center readings as the pan was heating. 

 

But I am puzzled that for one pan, steady state has the Freak measured temperature 15-20 degrees higher than the thermocouple measured temperature at the pan center, above the Freak sensor.   Does that mean the top surface of the pan is 15-20 deg below the bottom in steady state?   Sensor readings should not be **higher** than actual temperature due to any sort of coupling issue.   So is there a temperature gradient vertically across the pan thickness and if so, why is it larger for the Hestan pan and smaller for the Analon and Demeyere pans?   Is something wrong with the Hestan?  And if so, what?  Note that the Hestan pan is 3mm thick which might mean it has the thinnest base of the three pans.   

 

One thought here: the Control Freak's sensor is in the dead center of the pan, which is a centimeter or two from the coils. So heat has to be conducted to the location of the sensor.

 

If for some reason the pan's external cladding conducts heat poorly, it's possible that more heat could be conducted to the inside center of the pan than the outside center of the pan. I wouldn't imagine it would be 15-20 degrees, but it could certainly be some amount lower.

 

I would be tempted to try something with a completely non-clad construction like carbon steel and see if that behaves the same way.

 

As for myself — I am embarrassed to say that I haven't had a moment to play with my CFH since it arrived last week. I suppose this is the risk of chasing a discount!