We've spent years here at Serious Eats building a compendium of cookware information, covering nearly all you need to know about buying, caring for, and cooking in everything from cast iron and carbon steel to modern nonstick and stainless steel pots and pans. But there's one classic material we've written almost nothing about: copper. The reason shouldn't surprise anyone who's considered buying a copper pan and then seen the price tag. That sh*t's expensive!
And yet it's worth a look, in the same way a luxury sports car is of interest to just about any car enthusiast, whether they have the dough to buy one or not. The car analogy is particularly apt, since copper really is the fancy sports car of the cookware world. It's flashy, it's fast, and it doesn't come cheap. Though, to be fair, it sells for a hell of a lot less than just about any car, even the most basic one, and most people own at least one of those, right?*
I, a person who knows nothing about automobiles and who didn't get his driver's license until he was 29 years old, have no business writing car analogies. VROOM, VROOM!!
Given the historic importance of copper in the kitchen, and its continued use in higher-end French restaurants and some homes, it helps to understand a bit about it. Here we'll take a look at copper cookware to suss out its strengths and weaknesses, and try to help you decide whether you want to go deeper by investing in some.
Since Serious Eats is a media company and not an investment bank, we unfortunately aren't in possession of the types of funds that would allow us to buy a large collection of copper cookware on which to get tons of firsthand experience. To help fill in some of our knowledge gaps, we headed up to East Greenwich, Rhode Island, to visit Jim Hamann at the industrial complex where he runs his two copper cookware companies, East Coast Tinning (dedicated to vintage copper cookware restoration) and Duparquet Copper Cookware (where he makes his own line of copper pots and pans).
Jim gave us a tour of his factory, answered a litany of my copper questions, let me spin a couple pans with him, and allowed us to film him in action.
Why Use Copper for Cookware and Is it Worth it?
Copper was the first metal to be worked by human hands, and that history goes back a long, long time—about 11,000 years. That makes the human relationship with copper about as old as agriculture, though for several millennia we didn't do much with it beyond shaping it into decorative objects. Several thousand years later, but still some time before the Egyptians raised their pyramids, our ancestors figured out how to hammer copper sheets into bowls and other vessels. By the time of the Romans, if not before, we were using it to make cookware.
Copper is famed for its ability to conduct heat and electricity—it's no accident that it's copper and not iron that runs through the electrical wires in our walls—and it's this quality that makes it such an interesting metal for cooking. In a lot of ways, copper sits at the opposite end of the conduction and heat-retention spectrum as cast iron, making them two very different, yet complementary, materials for cooking.
Cast iron, as a reminder, conducts heat relatively poorly. It heats slowly and is prone to hot spots, but once it does get hot, it holds onto that heat very well. This makes it great for doing things like searing thick steaks, since you want the pan to remain hot when the cold meat hits it, which ensures the steak will sear and brown as efficiently as possible. Cast iron's great heat retention also makes it ideal for slow-cooking dishes that require sustained, even heat, like stews and braises, especially when placed in an oven, where the cooking vessel is heated from all sides.
Copper inverts these rules. It heats quickly and evenly, but it loses that heat just as fast. This responsiveness gives it a nimbleness and agility that can be very useful for delicate proteins like fish and seafood, as well as sauces, caramel, and chocolate—remove a copper saucepan holding a delicate sauce from the heat and its temperature will drop rapidly, reducing the chances the sauce overcooks or breaks from exposure to the retained heat in the metal.
If you'll allow this automobile-ignoramus to return once more to my car analogy, you can think of copper as the sports car of the cookware world, and cast iron as the pickup truck. They're both useful for certain—often very different—tasks.
That's the simple explanation, anyway. Put a handful of cooking geeks in a room and the conversation heats up faster than copper on a flame. Arguments erupt over whether copper is good enough to justify its cost, and whether its relative merits really set it far enough apart from the crowd of more affordable cookware.
Someone from the Modernist Cuisine team might point out that copper's unrivaled conduction isn't the full picture. They'd argue that burner size and the thickness of the metal are factors that are just as critical, noting that a 7mm-thick piece of aluminum heats just as evenly as a 2.5mm-thick piece of copper.
Inevitably someone else will refute that, arguing that the Modernist team only looked at evenness of heating and failed to consider copper's responsiveness—how quickly it heats up and cools down as more or less heat is applied to it. You can have copper's evenness with a 7mm-thick aluminum pan, they'll say, but you'll lose its responsiveness in the process.
An engineer, trying to keep the peace, will kindly put together a summation of the pros and cons of the primary cookware metals, explaining in lay terms essential concepts like thermal conductivity, heat capacity, specific heat, and thermal diffusivity. In the process, he will make a pretty good case that copper has a lot going for it. But then it falls apart when specific pots and pans get called into question, and ultimately everyone just starts trolling everyone else and we get nowhere.
And that, really, is the challenge: The relative performance of a pan—any pan—can be an extremely difficult thing to assess given the variations in mass, thickness, shape, size, and material from one design to the next. Not to mention that the effectiveness of any given pan is dependent on what's being cooked in it, and the experience of the hands using the tools in question.
I invite anyone who's up to it to try to wade into the more advanced physics to see if they can't come up with a more definitive answer than what's already out there, but here's where I've landed: copper is a unique metal with unique properties that make for some of the most deft and efficient cookware in the kitchen. Other options, including plain aluminum and stainless steel with a thick aluminum core, can rival (or come close to) copper in many—but perhaps not all—ways. Copper certainly loses on cost, but it wins on looking pretty freaking great, if looks matter to you.
So, do you need copper cookware? No, no more than a person who drives needs a sports car (or any other very expensive car). I've been working as a professional cook for 15 years in restaurants and food media, and I've rarely used copper. Most professional cooks rarely use copper, and you can absolutely cook great things without ever picking it up.
But should you eschew copper? No, no more than a car enthusiast should avoid buying a sports car. If you want a sports car, if you'd like the experience of driving a sports car, if you can afford and are willing to pay for a sports car, then yes, for sure, get yourself a sports car!
I want to add that I personally find a well-made copper pan to be an object of beauty in the kitchen, like a great piece of vintage cast iron, and that aesthetic quality can have value in and of itself. Its preciousness can remind you to pay more attention as you cook and, consequently, can help you cook better. At least, it does if you find meaning in the form of an object and not just its ability to accomplish a task.
The Quirks of Copper: Understanding Its Reactivity and Need for Linings
One of the key things to know about copper is that it's reactive. Acids like vinegar and tomatoes can leach copper into the food; over time, the ingestion of copper can be harmful. For this reason, most copper cookware is lined. What it's lined with is one of the main considerations to keep in mind when buying copper pots and pans.
Traditionally, copper was lined with tin. Tin is a pure element, like copper, and it has some fantastic qualities. First, and most critically for its role as a lining, it's totally inert—tin will not react with acids or anything else you would cook on it.
Second, and very importantly, tin is impressively nonstick all on its own, without any need for the seasoning we all strive to build up on cast iron. You can fry an egg, cook pancakes, or lightly sear a piece of fish on it and, for the most part, the food won't stick.
The downside is that tin has a low melting point of around 450°F (230°C), which a pan can quickly reach if left over a flame unattended and empty. For this reason, tin-lined copper should never be preheated while empty, and it should never be used for very high-heat searing (save your cast iron for that).
Tin is also somewhat soft, and can be worn away over time or damaged with metal utensils and abrasive scrubbing (I admit I have, on occasion, been a wee bit reckless and used a thin metal fish spatula on it). With care, a tin lining can last many, many years, but eventually even the most well-loved tin-lined copper pans will need re-tinning. While it's a rare event, you do have to factor that in when buying tin-lined copper, as it's an extra cost in the lifetime of the pan.
These days, though, the most common lining in copper pans is stainless steel. Lining copper with stainless steel is a much newer invention, since it's a heck of a lot more difficult to bond those two metals. The advantage that stainless steel offers is durability, just like any other stainless steel pan. The disadvantage is that it absolutely sucks in terms of adhesiveness: food loves to stick to stainless steel.
Also bad is that, while uncommon, if anything goes wrong with the stainless lining (say the lining decouples from the copper shell), you're probably out of luck. Unlike re-tinning, there's no easy way to fix a busted stainless steel–lined copper pan.
You will, on occasion, see copper lined with nickel, a practice that was briefly popular in the '90s, but has since fallen out of favor. More extravagantly, some copper pans are lined with silver. Silver, it turns out, is an even better conductor of heat than copper (not that conduction matters much with these ultra-thin linings), and it's supposedly very nonstick, though given the price, I don't expect to ever be able to confirm this firsthand.
In a few select cases, copper vessels aren't lined with anything at all. Jam pots, for instance, are made of bare copper since there's enough sugar in jam to prevent the fruit acids from reacting with the metal. There's also a plain copper mixing bowl intended solely for beating egg whites: the copper prevents sulphur atoms in the whites from bonding too tightly, helping to maintain the integrity of the foamy peaks.
What Makes a Good Copper Pan, and Where to Find Them
Aside from the lining material of a copper pan, the other most important characteristic that affects quality is the thickness of the copper. This can have a dramatic impact on the performance of the pan. The general wisdom is that copper cookware should be 2.5 to 3mm thick. Any thicker and you start to lose too much of the copper's rapid response to heat; any thinner and it won't heat as evenly as it should.
You're unlikely to find copper that's much thicker than 3mm, given its value and also density (copper is heavy, so adding more metal than is necessary just makes the pan that much more difficult to use), but you're quite likely to find copper that's less than 2.5mm thick. You're probably okay down to about 2mm, but any lower than that and you're getting into decorative pot territory: it may look nice in your kitchen but it won't perform well. This is where a lot of companies try to skimp, so make sure to confirm how thick the copper is before handing over your credit card.
Finally, the method used to produce copper cookware—whether it's made from spun copper, stamped copper, or rolled copper—is not determinative of its quality, even if spinning copper, as Jim Hamann does, requires a considerable amount of skill. Also, for those wondering about copper cookware that has hammer marks on it, while the practice of hammering copper was once used to strengthen the metal, today those hammer marks are almost always done by machine as a decorative gesture. They're mostly a matter of taste, and, again, not an indication of quality.
If you want some tips on where to find quality copper cookware, look at Hamann's tin- and silver-lined selections at Duparquet; the tin-lined pots and pans from Brooklyn Copper Cookware; and famous old-school makers like Mauviel and De Buyer, which now focus on stainless steel–lined pans.
A Quick Primer on Vintage Copper Cookware
As expensive as copper is, you can sometimes find a deal when shopping vintage goods (I saw one guy online who bought a pot worth hundreds for just $14). They key is to know what to look for. First, as mentioned above, is the thickness of the copper: it should ideally be 2.5 to 3mm thick (though down to 2mm is okay; larger stockpots are often thinner due to their size and weight).
If the piece is vintage, there's no chance it's lined with stainless steel, since that's a much more recent development. Nickel and silver are possible, but chances are an old piece will be lined with tin. The tin may have darkened—it darkens naturally over time, and you can use it with no ill effects—but if it's worn through to the copper below, it'll need to be re-tinned.
Old copper pots can come from many parts of the world, but if you're in the United States, chances are good that the cookware came from either the US, Britain, or France. There are some key details that can help you determine which country it's from.
The first is the shape of the handle where it attaches to the pot. Copper pots from the UK can be recognized by the sharp triangular shape of the pot-handle attachment, while French pots have a rounded triangle. American copper pots tend to mimic the French rounded triangle, but with a more elongated shape that can begin to appear bar-like (sometimes it's very bar-like). American pots also often have chunkier rivets than their European counterparts.
You can pick up more clues from the end of the handle where the hanging loop is. The French loop hole looks like a teardrop, whereas in the UK it's more of a keyhole or an arch. Once again, American makers (many of whom came from France) mirrored French practices with a teardrop.
Beyond the handles, you should look for a maker's stamp, which can provide clear info about who made the pan and where it was made. (Jim Hamann of Duparquet got his company name by registering an old abandoned trademark from an American copper cookware company that went out of business in the 1930s.)
No matter how dingy an old copper pot may look, remember that, short of extreme damage (say, a hole in it), it can be fixed up like new. After re-tinning and polishing, what may have looked like a piece of trash could easily be an object of remarkable beauty and value. Sure, it's no Porsche, but good luck finding a dingy-but-perfectly-functioning one of those at the local junkyard.