Unlined Copper Pan

Copper is prized in professional kitchens for one reason: it responds to heat faster and more evenly than nearly any other metal. For candy making, tempering chocolate, and delicate sauces where temperature precision is everything, unlined copper excels. The problem is chemistry — copper is a reactive metal, and it leaches into food when it contacts acids or salt.

The leaching concern is most serious with unlined pans. A pan made of bare copper in contact with tomato sauce, wine reductions, lemon juice, or vinegar will transfer measurable amounts of copper into whatever you're cooking. While copper is an essential trace mineral, excess dietary copper accumulates in the liver and can cause nausea, vomiting, and in chronic cases, liver damage. The tolerable upper intake for adults is 10 mg/day — a figure that can be approached with regular cooking of acidic foods in reactive copper.

Most copper cookware sold today is lined with stainless steel, which solves the reactivity problem entirely. Tin-lined pans are a traditional alternative, but tin melts at around 450°F (232°C), so they cannot handle high-heat searing or the dry heat of an oven above that threshold. Tin linings also wear away over years of use, especially with metal utensils or abrasive scrubbing, and should be replaced by a tinsmith once the copper shows through.

For most home cooks, copper is a specialty tool rather than a daily driver. A French copper saucepan is excellent for custards and hollandaise. A copper sugar pot is ideal for caramel. But for everyday sautéing, searing, or cooking tomato-based sauces, stainless steel or cast iron are safer, lower-maintenance choices that don't require monitoring the condition of a lining.