Tri-Ply cookware…What in the name of AllClad does this mean?

In response to my previous article on cookware, certain questions have come up. I answered one of those questions in an article on heat sources.

This next question is about cladding. Why cladding? As in AllClad, or Tri-ply or 5-ply or 7-ply?

First the cynical answer. In an effort to use technology to its fullest and get the most money for their marketing buck, cookware manufacturers have created ever increasing multiple layered cookware.

In the beginning, you had unclad, pure metals – cast iron, carbon steel, stainless steel and aluminum. You can still find cookware made of these materials plain and simple. In the case of cast iron or carbon steel you get excellent cookware that, when properly seasoned, give you quality naturally occurring non-stick surfaces. Aluminum also is very good cookware for certain purposes. Stainless steel is less than qualitative cookware but a good monetary value.

The next thing that happened is that two metals were combined to form a more perfect union of performance and quality.

So what is cladding?

Cladding is the bonding of different metals together to increase the function of the cookware. Most are trying to increase heat conductivity but some are looking for a means to improve overall thermal diffusivity. (What is thermal diffusivity? Read Part 1 of my cookware article.)

2-Ply -
In the best execution of 2-ply, you have copper pots and pans. Copper pans are most often sold in North America clad with stainless steel. Hence it is 2-ply or two layers of metal. In its best state, copper is simply coated inside with tin. I do not consider tin on copper to be a cladding as it is simply melted and brushed on. Neither do I consider the application of a nonstick or an enamel coating as a “ply”, although in the purest definition I guess one could call it a ply. I only consider it a “ply” when it involves a metal layer being added. Copper aside, 2-ply cookware is on the more affordable side and most likely not the best functioning cookware available. I say this because you normally see lesser metals bonded together, such as stainless steel inside and a thin carbon steel layer on the outside.

Some see bottom clad cookware as 2-ply; again, I guess that is true in the strictest sense, however for the purposes of this discussion I only consider the “ply” to be where metals are joined in a way that covers the majority of cookware surface.

3-Ply/Tri-Ply -
The best example here is AllClad. They pioneered the process of cladding metals for use in cookware. The most common type of this is stainless steel on the outside and inside with an aluminum core giving the piece its weight and energy conductivity. You may also see a copper core sandwiched between stainless steel. Another and more rare combination is carbon steel as the core element. One can also find stainless, aluminum and copper. However, in this configuration the outer copper layer is more for aesthetics than actual function. The price on the cookware is going to be based on the core element and the thickness thereof. For example, copper core will cost more than aluminum, which is normally more expensive than a carbon core. Another variable in price is the thickness of the core metal; generally, the thicker the core metal the more costly the piece.

5-Ply
I think you are beginning to sense a pattern here. Let’s see if you can guess the configuration of a 5-ply piece. Yes, stainless steel inside and out. Yes, an aluminum or copper core. That’s three. Stuck? OK. Let’s try adding the metal not involved in the core. So we have stainless, aluminum, copper, aluminum, stainless. And of course other permeations of those elements. One could also see silver in place of one of those layers as well. As you might imagine, the 2nd and 4th layers are very thin. If they weren’t, the pan would weigh a ton and be quite awkward.

7-Ply
At this point, we are entering the realm of marketing evil. Some companies claim 7-ply, but use the same metal in thin, bonded layers. Some companies use our familiar alternating layer pattern as seen above. We might see stainless, silver, aluminum, copper, aluminum, silver, stainless. And as we mentioned above, there are many permeations of these and other metals.

Above, I gave you the cynical answer to why cladding. Before I give you the better answer, I think we need to answer the other question on your mind. Are all these other layers (5 or 7) really providing measurable benefit? In my opinion, no they are not. I believe that well made, well constructed 2-ply or tri-ply cookware is all one really needs. Having said that, I find the sauce pans and saute pans made by Demeyere, which have these 7 layers, are very well engineered and are manufactured to a very high standard. Do I think these pans could be just as effective in a tri-ply design using a copper disk carefully enclosed in a well engineered stainless shell? Yes, but then again I am not a Belgian cookware engineer.

In conclusion, there is real benefit to be derived from bonding metals together in the manufacture of pots and pans. By making use of core metals with good thermal diffusivity combined with more durable, easy to maintain metals, high performing pots and pans can make their way into the hands of ambitious home cooks at a reasonable price.