Induction-Friendly Cookware Selection

[Johntodd]

1 hour ago, Laurentius said:

It's a terribly misleading video from a number of perspectives.  I could go into detail, but there are many doozers told here.

C'mon now, spill it.

 

If there is a small insert in the pan that does not cover the entire bottom then you will get those results.

 

[horseflesh]

4 hours ago, Johntodd said:

Here is a great video on why some pans are better for induction than others:

Why Some Induction Compatible Pans Work So Badly

 

The poster frame on that video shows a pan that I have, haha. It's the cheapest possible frying pan from a restaurant supply store. And indeed, it barely works on induction. 

[adrianvm]

When you say there is only one coil you mean the entire coil---both parts on both sides of the gap---just always fires up? 

 

I realized I had a compatible pan I hadn't tested---a Fissler pressure cooker with a very thick conductive disk base.  So I repeated my temperature test with the thermocouples.  I set the Freak to 250 F as before and after give it quite a while to settle (on low intensity) I got readings of 260 F at the center, 260 F at 2" off center and 246 F at 4" off center.  I waited several minutes more and got 254 F center, 254 F at 2", and 247 F at 4".   So that is the most uniform measurement I've seen.  I do again have the readings higher than the temperature reported by the Control Freak, which is a bit strange.  I wonder if hot air could be staying in the pan and heating the pan top surface.  (It's not clear why it wouldn't just rise out of the pan, though.)   If I blow into the pan for a moment the measured temperatures drop closer to 250 F.   This pan has tall sides. 

[adrianvm]

Why would I want to measure the sidewall?  I don't understand.  Presumably it will be much lower.  Do you think the temperature discontinuity at the sidewall transition would affect the temperature at the 4" radius mark, where the temperature was 247? 

 

Note that my primary motivation for testing the pressure cooker was that it's a representative of a pan with a very thick base that goes all the way to the edge of the pan.   It showed more uniformity than Demeyere Atlantis. 

[Laurentius]

3 hours ago, adrianvm said:

Why would I want to measure the sidewall?  I don't understand.  Presumably it will be much lower.  Do you think the temperature discontinuity at the sidewall transition would affect the temperature at the 4" radius mark, where the temperature was 247

Maybe because your data so far have been anomalous.

 

It's been my experience with disc-base pans that they tend to trap/ accumulate heat that would otherwise flow outward and up the sidewalls.  Some people think this is a good thing, but I don't.  The phenomenon is the one big reason thick disc pans are not responsive the way other constructions can be, even of similar thickness.

[adrianvm]

You think the pressure cooker measurements are anomalous?  They seem like the least strange data set of all the ones I've collected.  Maybe I should try the caramelization test with that pan. 

 

Are you saying that if I compare two pans that both have 3mm of aluminum but one has it as a disk and one is fully clad the clad pan will be more responsive?  It seems like it might be easier to cool down a clad pan because you would radiate more heat out the sidewalls, but also harder to heat it up for the same reason.   I don't know what the time scale is for that effect, though.  In my other tests it doesn't appear that heat is rushing to the outside edges of pans across the bottom, so I don't know why it would do it up sidewalls.  Your suggestion that heat "accumulates" suggests that we should see a higher temperature at the corner of the pan, which is not what I'd expect. 

 

I was curious about whether the thick disk construction would result in a more even temperature across the pan surface compared to thinner clad and disk construction.  It seemed like it did do that---so a thick disk may be better for uniformity.   Clearly a thick disk is going to sacrifice responsiveness, so it depends on the relative importance of these two metrics.

 

[Laurentius]

13 hours ago, adrianvm said:

I was curious about whether the thick disk construction would result in a more even temperature across the pan surface compared to thinner clad and disk construction.

 

Yes, although I'd express it as: thick disk does a better job of mitigating the intrinsic unevenness of induction.

 

You can think of your hypothetical 3mm clad pan as being all disc.  For instance, a 28cm Demeyere Proline is formed from a flat disc that is about 34cm in diameter.  There's close to the same volume of aluminum in that pan as there is in the thicker but much smaller disc of say a Fissler OP or a Paderno GG.

 

A problem with these tests on empty pans is that comparisons require waiting for the pans to reach thermal equilibrium.  Virtually no cook waits that long to preheat.  If you peruse Centurylife.org, you can see that Franz's evenness rankings suffer from this, as well as setting an arbitrary time-to-temp criterion well short of equilibrium.  Basically, pans that heat up faster are awarded a low handicap.

 

And of course food has it's own conductivity and other thermal properties within a realistic system.

Edited May 28 by Laurentius
clarity and misspelling (log)

[adrianvm]

I tested the Fissler pan again and this time measured the center, the inside corner, and a spot an inch up the sidewall on the inside.   I heated the pan on slow to 250 as before and the center temperature came to a steady state around 265 F.  The corner of the pan was 250 F.  That was pretty surprising.  The temperature up the side wall was 201 F.  I got to wondering whether that sidewall temperature was actually measuring convective heating from the inside bottom surface, so I moved the thermocouple to the outside of the pan side and there I got the reading of 168 F.  None of this seems particularly surprising.  There's no indication that heat is "accumulating" at the corners or in the sidewall as suggested above. 

 

I also tried another caramelization test, this time with the Freak set at 375 F, where I let it come up to temperature and then sprinkled sugar into the pan.  The fissler gave a very nice result with a very even brown across its surface.  The demeyere dutch oven (which is the same diameter) left a ring of white sugar around its edge, showing that it is definitely not heating as evenly as the fissler. 

 

Another bit of information:  I finally got Cristel to give me a number for the thickness of their disk based pans.  They report that the pans have 4mm of aluminum in the disk bases in the Mutin and Strate lines.  My understanding is that Fissler and Paderno have more aluminum, so the Cristel may outperform clad pans in terms of uniformity, since they typically have 2.3mm of aluminum or less, but it won't be as uniform as Fissler or Paderno. 

 

 

[Laurentius]

13 hours ago, adrianvm said:

There's no indication that heat is "accumulating" at the corners or in the sidewall as suggested above. 

It is accumulating in the center, as your data suggest.  They also verify that there is a gross thermal discontinuity at the sidewall--that was my meaning.  This large Delta T means foods stuck to or propped against the sidewall will receive a lot less heat than foods on the floor.  And liquid foods will have less complex convection currents.

 

IMO, you've reached the Realization Point about evenness on induction:  If very high evenness is important to you, you must choose very thick disc-based constructions.  But that choice entails slow downward response and effectively no sidewall heat.  If those aren't disadvantageous to you, then the Fissler OP type pans are good choices.

 

And of course the other realization is that the Control Freak doesn't produce completely even heat with any pan.

[palo]

I wouldn't suggest "accumulating" is the correct term for this instance. What you're commenting on is the migration of applied heat from the source.

 

p

[adrianvm]

Sidewall heat on induction is going to be negligible no matter the pan, is it not?  When I tested my Demeyere Proline skillet the temp was 205 on the sidewall, and that's a pan with a conductive sidewall.   If I use a clad pan, which seems to mean higher Delta T, then food that's anywhere close to the edge---not just the food that's touching the edge---will receive a lot less heat than foods at the center.  That's not an improvement.  It's a bit unclear to me what the benefits of sidewall heating are. 

 

Cast iron seems to be better at browning food than anything else.  I recall a situation where I cooked half the meatballs in the Demeyere Proline and half in a giant cast iron skillet and the ones in the cast iron browned while the ones in the Demeyere did not.  And the Demeyere was on the more powerful burner.  They were very wet meatballs that were hard to brown.  So what is the explanation for cast iron's ability to brown?  It seems like aluminum has a 5x higher thermal diffusivity I would think would enable it to transfer heat to the food faster.  Aluminum also has double the heat capacity of cast iron, so it holds twice as much heat per mass.   So what's the magic with cast iron?  Can I get the same browning with something that heats more evenly?  Is it simply about the mass of the pan? 

[horseflesh]

I had some Costco credit and a need for affordable new pans so I decided to try the Henckels knock-off of Hexclad pans: Hxagon.

 

https://www.costco.com/henckels-hxagon-3-piece-skillet-set.product.4000209381.html

 

A cheap knock-off of an overrated pan, how good could it be? Well, so far I think they are ... Not bad.

 

When searing in the biggest pan, and then making a pan sauce, it was easy to see the heat was pretty even. I was actually very pleased with how my seared pork tenderloins came out. And when I made some caramelized onions in the medium pan, it was ... Fine. No complaints. 

 

They are not really non-stick, but low-stick. An egg cooked without oil or butter will not slide around, but can be loosened without destroying it. (I knew this going in but those who are hoping for full Teflon slipperiness will be disappointed.) 

 

The pans are easy to clean... In slipperiness and ease of cleaning they seem similar to Circulon hard-surface non-stick pans. 

 

These pans also have a perfectly flat and non-textured bottom which makes them good for the Control Freak. The smallest pan isn't quite heavy enough to push down on the CF temp sensor, though. Even with a single egg in it, the small pan sits at an angle, resting on the springy sensor without fully depressing it. It needs just a little more weight to sit flush, so depending on what I am doing with the tiny pan I may need to keep a wooden spoon resting on the edge to maintain good temperature control. 

 

For the money these seem to be reasonable pans. 

 

If anything interesting happens down the road I will post a follow up.