Few activities are more basic than cooking, and few metals used in the preparation of food are more basic than copper, which is just one of the reasons why copper cookware is the choice of amateur and professional chefs alike. Beyond this primal appeal, copper distributes heat more evenly than other metals or alloys, so much so that many stainless-steel pots and saute pans feature a layer of copper on their undersides. Sometimes, though, the contribution of copper to our diet is even more direct—according to the World Health Organization, we should all ingest 1.2 mg of copper daily. Fortunately, there’s plenty of copper in foods like lentils, shellfish, and chocolate, all of which are preferable to gnawing on the edge of your favorite copper mixing bowl.
Copper has been used continuously by Homo sapiens for some 10,000 years—a copper pendant from northern Iraq is the oldest example of the metal being formed into something beyond its natural state. Like gold, copper can be hammered cold into shapes, rolled flat, or melted and cast. Most pieces of copper hollowware—from pudding molds and tea kettles to pots and pans—employ a combination of these techniques. Typically, a rolled sheet of the metal is either pounded into its desired shape if it’s not too deep (a saute pan) or cut into a rectangle and formed into a cylinder for a tall item (a stock pot or tea kettle), whose base will be attached as a separate piece.
Seams between pieces of copper are often joined together via cramped or castellated joints (sometimes imprecisely called dovetail joints), which are pounded flat and then sealed by brazing. Lockseam joints are produced when a sheet of copper is folded back on itself at its meeting edges to create a pair of J-shapes, which can be hooked together, pounded flat, and soldered to make the seam watertight.
Of the manufacturers that have made copper cookware for the kitchen over the years, Revere stands out. Founded in 1801 by the American patriot and silversmith Paul Revere, Revere Copper and Brass Incorporated of Rome, New York, was making tin-lined copper hollowware back in the 1890s, and the company introduced its Revere Ware, which replaced the tin with stainless steel, in 1938. After World War II, Revere Ware took off, but in the 1950s it faced stiff competition from imported enamelware, especially Le Creuset, whose brightly colored pieces were a fun, cheerful alternative to the stodgy appearance of steel and copper.
One of the chief drawbacks of copper, besides its high price, is that raw copper exposed to air will form a green patina called verdigris. Though pleasant to look at (think of the green patina on the Statue of Liberty) it is poisonous to eat, which is why copper was tinned, and subsequently sealed behind stainless steel by Revere, in the first place. Still, some cookware is traditionally made of copper, and worth the elbow grease to remove the verdigris for the cooks who love them. Oblong fish steamers, for example, are often made of copper, as are double boilers and saucepans. In some cases, such as round-bottomed copper bowls designed for whisking egg whites, the copper is considered preferable to stainless steel or glass—egg whites whipped in copper are less likely to become overbeaten. In other cases, such as with cookie cutters, the classic look of copper permits these kitchen tools to be displayed on a wall or shelf when not in use.