Is copper cookware really better than stainless steel?

Question

This is somewhat related to the question about copper vs. cast iron, but this is about copper vs. pure stainless steel.

I had an old stainless steel stockpot that warped (it was very, very cheap stainless steel, paper thin) and have to replace it ASAP. I have a family member with a few connections that gets a deep discount on one of the more expensive brands. I asked her to look into getting me a copper stockpot (lined with stainless steel, of course, so the reactivity problem more or less goes away), and got this response as an explanation to why it is apparently unavailable here:

[...] there is apparently no advantage cooking-wise to using copper, and people just buy it for the look.

[...] None of our big accounts, including [XYZ] etc even had any interest in stocking it, which is why we never brought it in.

Note that these stores do carry the same brand of stainless steel products, just not copper.

Now, I am taking this with a grain pile of salt because (a) this family member never cooks and (b) the advice came from a marketing manager who obviously wants to push the products that are available locally. Nevertheless, I think it's worth asking people with knowledge/experience:

Is there actual evidence confirming any of the advantages of copper cookware (durability, conductivity, heat spread, etc.)? Has it actually been proven anywhere that copper is (or is not) superior to stainless steel?

Or are articles like these just parroting a bunch of myths?

I'm looking for strong evidence here, so please answer only if you are prepared to back it up.

Clarification (with apologies to Ward): I am looking for evidence of the practical benefits. It's obviously indisputable and easy to look up the fact that copper is a better conductor than steel, and lighter; the question is, does this matter with respect to responsiveness, hot spots, and so on?

Answer 1

Modern stainless steel pans with clad bottoms can be as good as copper pans.  McGee developed a simple technique to test the heat distribution where he fits a piece of paper to the bottom of the pan, placing the pan over a burner and carefully watching how the paper browns.  Thick aluminum, clad bottom stainless, and copper all worked equally well. 

There are differences that relate to the techniques used in cooking.  A thin copper pan is great for melting butter or chocolate straight on the burner.  Modern air-gap wall stainless steel pans hold the heat better and work better for simmering or boiling.  Copper is harder to upkeep.

Pans will develop hot spots, even copper which is the better conductor. Until we get graphite added to the cladding  or some other exotic material to distribute the heat, thickness will matter the most for even heat distribution.

I have read several consumer tests and reviews of pans and they fail to note that thermal conductivity and thickness can both be used in practice to balance the temperature distribution and heat flux in a pan.

Answer 2

I will add my (admittedly somewhat subjective) experience with using both copper and stainless. I have a couple of copper pans (all stainless lined) that I got as gifts and also some high-end stainless ones, and they're comparable in thickness (both bottoms and sidewalls), though the copper is heavier due to cast bronze handles.

If I try to cook rice in the copper saucepan the same way I do it in the stainless one, I have to use a lot more water, or I have to turn the heat down a lot more. The copper pan seems to get hotter farther up the sides of the pot, which boils away the water faster, given the same flame setting on the stove.

I've also found that my copper skillet heats over the whole bottom of the pan faster. If I want to reduce a sauce, I use that one because I'd get boiling over the entire bottom of the pan, rather than around the edge and in a few hot spots. The stainless (and even cast-iron) pans will eventually heat fairly evenly over the entire surface, but the copper pan seems to do so much more quickly, so reduction happens faster.

On the downside, the handles on my copper pots get hot faster than my stainless ones (which I attribute to the better conduction up the side of the pot, and possibly the copper content of the bronze handles). Cast-iron handles get hot about the same as the copper ones.

I have not noticed much difference in heat retention when off the heat, though.

I would not bother buying a copper stock pot, since I can't see any particular advantage it would grant. The things you cook in one would not benefit from the (admittedly small) differences I've noticed in my other copper. The copper saucepan is nice and works like high-end cookware should, but sometimes I overheat things in it. I like the skillet a lot for when I want the whole surface uniformly hot, and it excels for reducing liquids. Knowing what I know now, I might be tempted to purchase another copper skillet if mine were stolen, but I probably wouldn't replace the saucepan with copper again.

Answer 3

Copper is a good conductor of heat: its thermal conductivity is an order of magnitude higher than stainless steel's. I think anyone who's paid attention while using different types of cookware has seen the evidence for themselves of how this is beneficial: you get more even heat distribution and you don't get hot spots like you do w/ stainless, especially the thin stuff that has no laminated copper or aluminum layers.

Answer 4

I am continually replacing my commercial 18/10 stainless with clad bottoms for all copper lined pots and pans; a piece here and there; Ebay, flee markets...etc. I'm a chemist and a "shade tree" chef with one of those analytic minds that called bullshit real quick on "hype", especially pretentious "well marketed" luxury items i.e. I invest in performance because of the benefits.

There's a saying "stainless is painless" . It can take a beating when you occasionally have to restore it with Easy Off oven type cleaners to get the baked on crap off of it. And since you should polish copper vs using oven cleaner, I give this benefit to stainless. So, if I'm cooking, I try to keep the surfaces clean so food doesn't get cooked on. This may not of course be as easily done in a commercial kitchen however I still see most fine food chefs choose lined copper anyway.

So, the benefit I've found is that Copper simply heats faster, more evenly and radiates from all sides. If you make anything like a stove top lasagna or melt velveta, chocolate, or make anything that might tend to burn on the bottom if you don't keep stirring it, copper simply brings food up to temp quicker but when it done, you can simply turn off the heat and it cools very quick so the metal doesn't "hold" the heat so you don't overcook food or burn on the "hotter spots". Basically, the better the heat distribution, they less the hots spots, subsequent uneven cooking/burning food.