Relied on for their beauty and durability, copper pots have the ability to conduct heat evenly, which makes them a smart choice. Acidic ingredients, such as tomato sauce and lemon juice, can react with the copper, even without heat, causing the metal to dissolve and discolor the food. To avoid the intestinal discomfort this causes, choose only copper pots that have been lined with another metal when cooking acidic foods like tomato sauce.
Choosing the Perfect Pot
Most copper pots are lined with either tin or stainless steel. Both metals have their pros and cons. Tin is more economical and quickly conducts heat; its downside is that it wears down quicker than stainless steel -- usually in about 15 years -- exposing acidic foods, such as tomatoes, to the copper underneath. Some manufacturers of copper cookware re-line worn copper pots, while other companies offer innovative cookware made with a combination of copper and stainless steel because the steel matches copper's durability.
Understanding Copper Cookware
Your cookware might be made with copper even if you can't see its telltale coloring. Copper is often sandwiched between other metals and used as a core because of its ability to conduct heat. The other metal -- usually stainless steel -- provides a safe cooking interior, and also covers the outside of the pot, preventing it from tarnishing. Stainless steel doesn't wear down or melt under high heat like tin does, so you are assured of the pot's safety when cooking acidic ingredients such as tomatoes. High-end copper cookware designed for professional chefs is lined with silver for cooking temperature-sensitive desserts, such as Italian custards and pastries.
Uses for Unlined Copper Pots
Unlined copper pots are beautiful to look at and work perfectly for whipping up non-acidic confections such as cream and egg whites when making airy treats. These unlined bowls are prized by pastry chefs for their ability to keep cold ingredients cold; in candy making, unlined copper kettles are used for their superb temperature control and ability to conduct heat evenly. When polished, unlined copper cookware also makes for stunning decoration when hung on your kitchen wall.
Tarnished Pot Safety
Copper oxidizes over time, causing it to develop a greenish color known as patina. Although the discoloration may not look attractive, it will not affect your food. When cooking tomato sauce in a tarnished copper pot, look first at the condition of the lining inside the pot. This will tell you whether or not the pot is suitable for cooking acidic ingredients. Older pots lined with tin may not be safe for cooking tomato sauce.