There are many good articles on the net which go into that sort of detail. I will only tell you about the terms and try to tie them to what you will see out in the retail jungle. I don’t believe that teaching all the technical aspects of cookware metals makes you a better consumer. Article source: Street Directory
1.) There is heat conductivity. This simply indicates how well a metal disperses energy (heat from a flame or burner) over its surface. Copper is far and away the best conductor of energy. It is almost twice as good as aluminum. And the two are way ahead of the other materials.
2.) There is also heat capacity. This tells us how much energy (heat) a metal can hold. Cast iron holds more heat than copper and you might be surprised to know that stainless steel is second only to aluminum in how much energy it can hold.
People have come up with a combined measurement of these two topics called thermal or heat diffusivity. This is a fancy way of saying take the two numbers or terms above together and create a single measurement. Copper is first, followed by aluminum, cast iron, carbon steel and stainless steel.
Now there are wild cards here like thickness of the metal and combined metals.
OK, let’s start with thickness. Yes, a thicker metal will have a better diffusivity, but cast iron will never surpass copper or aluminum in overall performance no matter how thick. But can say 5 mm of aluminum perform as well as 2.5 mm of copper. Yes, to some extent, but it will never be as responsive. When shopping for cookware, just be aware that thickness isn’t always better yet it will factor into price.
Next, are combined metals better than pure or single metal cookware? This is where marketing and science come into play. Marketing types will try to convince you with science that their particular design is superior. As for whether there is cooking difference, that can be debated. In my opinion, combined metals will, in most cases, make better cookware, providing the manufacturer has a good reputation and the products are made of good quality materials.
However, we need to look at a pan being made entirely of or completely covered by the superior metal. Also, does the superior metal cover the whole area of the pot / pan or just the base? Combining metals can give you the best of each metal and it can make cooking enjoyable for the home chef. For instance, a 5mm aluminum core skillet with stainless steel inside and out will give you the benefits of aluminum’s thermal diffusivity and the ease of use and durability of stainless steel. An all copper skillet with stainless steel inside, will give you the superior performance of copper with the ease of use and durability of stainless steel. I have used copper pots and pans, aluminum base and copper base pans and find that the performance differential is negligible, depending on the task. Yes, an all copper skillet will live up to its exalted reputation. A thick all aluminum pan will also perform well. Do I notice a difference between the copper, the 5mm aluminum core Demeyere skillet, my industrial grade aluminum skillet and my copper base Sitram skillets? Yes, I would have to say the copper, Demeyere and Sitram perform far better than the pure aluminum and the Demeyere skillet is better than the Sitram.
But that leads us to the obvious question of whether the higher cost of copper and Demeyere or Viking equate to an equal level of superiority: well that is for each to decide. For me, it is does not. Copper remains the best and the highest priced, but by comparison I believe that these other types of cookware come close enough for most of us, and combined with the savings in cost make them viable options for gourmet cooking. Within each sub-classification below you will find the same axiom applies. For instance, Allclad isn’t always proportionally better than other brands of tri-ply cookware.
One other thing to keep in mind is that certain metals that are better at certain tasks than others - copper, cast iron and aluminum for skillets, enamel coated cast iron for braising and slow cooking, cast iron skillets for high heat frying, you get the idea. I cover this topic in each descriptive area below. My point here is that one doesn’t need to buy every piece from one class of cookware or manufacturer.
In : Cooking & More