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Cookware 46

Cirarello Signature Series "9-Ply" Skillet

kaleokahu | Mar 9, 2015 01:25 PM

Hello, All:

Friend and fellow CH randallhank graciously sent me this 8" skillet for destructive testing. If you haven't followed the discussions about this line, it is somewhat unique, in the sense that it is BOTH a clad and disk-bottom construction. More accurately, it's a triply pan with a thick disk bonded on the bottom. Specifications for its construction were never published, and it's been a mystery how much of what is inside. Hence Randy's and my curiosity, and hence this review:

Review of Michael Chiarelli Signature 8” Skillet©

Some might question the utility of reviewing something that is no longer offered at retail. Frankly, I do, too. However, this line (made by Meyer) is a somewhat unique hybrid construction, and other respected cookware aficionados give it high marks for features and performance, especially even heating. Another factor, too, was that I was given this pan specifically to destroy it, so I thought I might as well cook in it and review it before I put it through the bandsaw.

The hybrid nature of this pan is obvious with the first look. It is fully clad, meaning that the lining and the exterior walls are the bread in a SS-Aluminum-SS sandwich. Nothing too remarkable there. But this clad pan also has a thick disk bonded to its bottom. All that is visible from the exterior is an induction compatible SS cap and a tall band of polished copper, suggesting a thick sheet of copper lurks inside.

I can find no published specifications about this pan’s construction or inner layers, but its performance, weight and palpable thickness inspire a look inside.

1. Physical Attributes & Dimensions

The pan’s bears an inset circular medallion cast into the very center. Between borders, it reads:

9-Ply Clad Base
8in/20cm
Michael Chiarello Signature Series
I QQ07
Superior Heat Conduction

Despite the markings, the pan is actually nearly 9” (22.5cm) in diameter, rim to rim. Its circular interior floor surface is flat out to 14.4cm (about 5.6 inches), and then slopes up as skillets do. The total area of the pan’s floor is 162 square centimeters, or just under 25 square inches. This is basically a 1-egg pan.

This medallion is 7.5cm in diameter, which would be irrelevant if it were not inset. However, it is deeply inset—at least 1mm-- and all that writing is further inset another half millimeter. What makes it relevant is that this 75mm-diameter reduces the overall thickness by >1mm in the center of the pan.

The bottom disk is 15.5cm in diameter, meaning the disk diameter is 1.1mm larger than the pan floor. This is important, because it shows the entire floor is protected by the disk, and therefore there should be no “circle of fire” as is found on cheaper disk pans.

However, the disk is tapered, so the surface in actual contact with the hob is only 13.8cm in diameter. When I ran the calculations, I was surprised to find that only a 13.2mm flat band actually contacts the hob, and this area totals a measly 104 square centimeters (about 16 square inches). The practical cost of insetting the medallion was to sacrifice 30% of the available contact area.

Measuring with a machinist’s rule and straightedge, the pan stands 52.8mm tall at the rim, which is formed into a pouring edge. From the interior floor of the pan to the rim, it measures 44.8mm, meaning that the supposed 9 layers of base total around 8mm in thickness. Due to the medallion being inset, this looks to be more like 6.5mm at the center of the pan.

The massive, hollow-cast SS handle is 20.3cm (8”) long and attached by two surprisingly large rivets.

Accounting for the handle being attached to the sloping part of the sidewall, the total length of the pan is 40cm, so it would fit into a 16” cabinet. The smooth handle is rectangular in cross section, is slightly arched, tapers slightly toward the pan body, and has an integral hole for hanging.

The exterior is brightly polished except for the base’s contact band. This band and the pan’s interior have been concentrically brushed.

The brush is coarser than many pans I’ve evaluated, but still not rough.

2. Performance & Use

Despite its small size, heavy handle, and the whole medallion/band thing, this pan sits rock solid, even empty, and even on a radial gas grate. It also sits dead flat on glass. The handle is comfortable using either an underhand or overhand grip. The grip is secure despite no real texturing, finger grooves or thumb rest. The handle did warm up under heat, but did not require a side towel.

I cooked in it for several days before breaking out the IR and contact thermometers. The first prep I made was very low-heat French-style scrambled eggs on my 5” triple ring gas hob. These eggs are usually done in a double boiler, because they’re stirred continuously while adding butter. I wanted to get a feel for how long it took for the eggs to start coagulating, how even the coagulation occurred across (and up) the pan, and how sticky the liner is. My first reaction was that this pan takes a long time to heat up. Starting from ambient temperature, four medium eggs took a good 3 minutes over a medium-low flame to begin to coagulate. The rougher-than-normal texture of the lining did not stick at all until curds began forming, and ultimately did not stick any more than my smoother comparison pans (e.g., a Williams-Sonoma Thermoclad, also made by Meyer). However, at about the time that curds started forming in earnest, serious sticking began at the walls, beyond where the disk ended. Other than this boundary condition, however, I found no unevenness at all. In fairness, a 6” bottomed skillet on a 5” gas hob is going to have some serious heat flowing up the sides, so it’s not surprising that the walls stuck so badly. Still, the very thin aluminum layer in the pan body was not enough to move this heat away effectively.

As I cooked in it, my initial observations about responsiveness were confirmed—it takes a long time to heat up and cool down but the Chiarello is exceedingly even. This can be seen in the “scorchprint” photos.

This left photo is of the flour-coated pan after 10 full minutes on a medium low flame; it took another 5 full minutes to toast the flour to the level you see in the right photo.

Then, once the pan had cooled, I tested with the contact thermometer to see how long, over medium heat, it took to go from 60F to 350F, and back down to 250F. It took 3:12 to reach 250F, and 5:55 to reach 350F. Completely removed from the flame and placed on a cool gas grate, it took 2:35 to return to 250.

However, as the thermometers verified, the heat was exceedingly even, plus or minus 5F, across the entire floor. Strangely enough, as the pan was coming up to heat, the center inset “medallion” area was actually slightly slower to come up than was the band which contacted the grate. The widest temperature variations were between the floor and the walls, the latter being consistently 25F hotter than the floor. Note: this extreme evenness may be attributable to the fact that the 6” pan bottom was mated almost perfectly with the 5” gas triple ring. Query whether insetting the medallion was a deliberate attempt to alter the Chiarello’s thermal characteristics.

The flow of hot exhaust gas would also explain why the walls were appreciably hotter. It would be interesting to see if the evenness I found extends to a larger-footprint pan on the same hob.

3. What’s Inside?

Easy part first. The aluminum in the sidewalls is exposed at the pouring edge. Unlike many lines which bevel this edge, the Chiarello skillet is cut square, so that the thickness you see is the actual thickness. Basically, the pouring rim has a large radius, and the rim ends parallel to the floor. Cutting it square therefore renders the exposed edge perpendicular to the floor, making measurement easy. The rim mikes at just under 2mm. The SS liner layer is thin, looks the same as other lines I know to be 0.2mm -0.4mm; the exterior SS wall layer looks the same. Arithmetic tells us the aluminum layer sandwiched between is less than 1.5mm thick. This is thin for quality clad (compare Thermoquad at 2mm, and 5mm for Demeyere Proline).

But remember this is a hybrid pan. There’s also a thick disk attached at the bottom, ostensibly with thick copper inside. Basically, if the clad pan body is nominally 2mm thick, what’s in the >6mm that lies beneath?

I should note here that the copper band on the exterior is not square with the pan floor. Instead, it’s beveled at about a 45-degree angle. This leaves the impression that the band is a functional solid layer of thick copper almost 10mm thick. Obviously 10 is greater than 6, so it’s also obvious there isn’t 10mm of copper here. But how much is there, really? With this in mind, I set about destructive testing.

4. But First, Let’s Mess It Up

Before I fired up the bandsaw (and used all 10 fingers one last time), I thought I might as well really torture this pan in other ways before the vivisection. Specifically, I wanted to see if I could: (a) salt-pit the lining; (b) warp the pan; and (c) delaminate it. This is intentional abuse, to be sure, and not something which would fall under “normal use”. However, accidental misuse of these types is to be expected to some degree over the course of a cook’s love affair with a pan.

I first scoured the interior absolutely clean with Bar Keeper’s Friend, dried it, and then filled it with cold water. To that water, I slowly poured a Tablespoon of coarse Kosher salt dead center in the pan

I then put the pan on medium-high heat and boiled it dry, without stirring. I got a few spots, but BKF removed them. Then I repeated the process. On the second round, I got spots which BKF would not remove.

These have just the tiniest bit of texture to them, so yes, in two tries, I was able to salt-pit the pan. However, the pits are nowhere near deep enough (yet) to have breached the lining .

Second in the torture progression was warpage. I heated the empty pan until the surface temperature reached 600F, then quenched the pan in cold water. Result? It warped the pan—to the extent that both the rim and the base took on a moderate (approximately 2mm) warp. This would still make it serviceable on a gas or electric hob, but would render the Chiarello a real problem on a glass top. There was also a small but noticeable gap in the copper band; I couldn’t tell whether it was superficial in the band itself or systemic in the sense that the entire disk was beginning to delaminate.

Next up… Delamination proper. I arbitrarily decided that if the empty pan could survive longer than 10 minutes over a high gas flame, I would spare it more gratuitous abuse. I don’t know for sure exactly how hot it got, but by 6:33, molten aluminum started dripping out between the disk and the pan body , so I stopped the test (because I still wanted to measure how much aluminum is inside).

Actually, I was hoping that it would cleanly delaminate, making it easier to mike any separated layers, but now I had to saw her open...

It had always perplexed me how this pan’s makers could claim that there were NINE layers inside. The numbers just didn’t make sense . I knew there were the 5 visible layers:

1. SS liner (≈0.2mm)
2. Aluminum “wall core” (≈1.4mm)
3. SS wall exterior (≈0.2mm)
4. Disk (including copper) (≈6.5-8mm)
5. SS pan bottom (?)

But what could account for 4 more unseen layers? Experience and common sense told me that the missing layers were probably two aluminum layers, and two more very thin bonding layers—ones intended to make other layers stick together better, rather than included to increase conductivity. Demeyere, for instance, has used silver as very thin bonding layers between dissimilar metals in its cores. Other makers use slightly less conductive aluminum alloy layers as bonding layers because they bond firmly to both copper and pure aluminum, which themselves don’t bond well together.

5. Cutting In

When the metal shavings stopped flying and I looked at the pie-shaped test piece (called a “cutaway”), as my hero Gomer Pyle used to say: “Sur-prise, sur-prise, sur-prise!"

Note the voids where the aluminum had melted away, and the step at the medallion.

That copper band—made to look like it is as thick as 10mm—is exactly 0.66mm thick! I was able to mike this layer accurately because what I thought was a partial delamination in the warpage test was actually this thin sheet of copper simply bending away from the pan wall. When the cutaway piece fell free, I simply folded the copper back--with my fingertips--and measured it with the micrometer.

I had cynically expected 1mm or maybe 1.5mm of copper. Copper’s expensive. But I wasn’t prepared for 66/100 of a millimeter. To make matters worse, the copper in this Chiarello isn’t even really a layer! It doesn’t extend across the entire pan bottom; rather, it’s embedded into the aluminum core only about 2.8cm all around. There’s no copper at all at the center of the skillet. The bottom line here is: the copper is so thin it’s purely ornamental. I would also say deceptive.

Once the cutaway out, I was also able to mike the overall thicknesses with great accuracy. The floor thickness at the inset medallion is 7.81mm, and at the contact band it is 8.96mm thick. And the overall wall thickness was 1.90mm.

Judging the thickness of other individual bonded layers is a visual exercise, under magnification and with the machinist’s rule. I judge that the liner, pan wall exterior, and pan bottom SS layers are each 0.4mm thick. As a matter of arithmetic, that makes the aluminum core in the walls 1.1mm thick. The next layer is obviously aluminum, then the copper (around the periphery), then an equal thickness of aluminum. So what we finally have in the cutaway is this:

1. SS liner 0.40mm
2. Aluminum “wall core” 1.10mm
3. SS wall exterior 0.40mm
4. Aluminum 3.00mm
5. Copper 0.66mm
6. Aluminum 3.00mm
7. SS base 0.40mm
=======
8.96mm

But wait, where are layers 8 and 9? I soaked the cutaway piece in lemon juice overnight to try to bring out more contrast in the layers, but still only 7 layers were visible. Moreover, the aluminum layers in the disk appear to be only two in number, so it does not appear that Meyer mixed 4 aluminum disks of different alloys in the base. So my judgment is that layers 8 and 9, if they exist at all, are some extremely thin flashings of silver solder somewhere in the stack. Again, deceptive to claim there’re 9 layers, when in functional reality there are only five.

6. Conclusions

This is (was) a beautiful, robust-looking, hefty pan with great ergonomics and ease of use. It is thick, exceedingly even-heating, with no hot spots, rings, etc. Practically speaking there simply are no temperature differentials that would make a difference in cooking (although cooking 4 scrambled eggs on gas did cause some sticking on the 25F-higher walls). However, the pan is poorly responsive because of its several layers of SS swaddling a thick core. Its hybrid clad nature and thickness results in it taking a long time to come to heat, and a long time to respond to downward heat adjustments.

I think the Chiarello skillet would make a great pan for those cooks who know in advance what the correct setting is for the desired preparation and want to leave it there, for, e.g., pancakes, steaks, etc. It would, I believe, be very heat stable once in equilibrium. But cooks who adjust heat as they go would likely find themselves overshooting, with no going back. Kind of like steering an oil tanker-- slow to answer her helm.

The Chiarello is also, despite its appearance, a somewhat fragile pan. It salt-pitted easily. It warped noticeably under conditions where a cook might easily (albeit mistakenly) drop a hot pan into a sink. And finally, it melted, dripping molten aluminum after only 6 ½ minutes of inattention. On my open gas hob, these dribbles fell harmlessly onto cast iron. I’m not willing to risk my Ceran cooktops finding out what 1,220F aluminum falling onto them would do.

Overall, the hybrid design seemed to work, and is an improvement over basic disk-bottomed pans. But I’m dismayed by Meyer/Chiarello’s deception with the copper, and touting 9 layers when in reality there are essentially only five. I can better understand why they never published the line’s true specifications.

Aloha,
Kaleo

© 3/7/15

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