Is it because copper isn't good to eat food from?It's not poisonous though right?
It's lined with tin....Not steel. (normally). And, it's because copper is toxic if ingested in larger than minute quantities. And, cooking in a copper pan could exacerbate that condition
its a VERY good conductor it also reacts to acids though, and is also MUCH more expensive so it doesn't make sense to make the sides of pots out of copper, since they don't have to conduct heat, and the inside is usually coated with soemthing to help it resist acids.
If you get too much copper in your food from cooking in pure copper pots, you can get a buildup and the symptoms of copper poisoning are similar to mental illnesses.
Copper is reactive with acidic foods, it will leach or shed into whatever you are cooking and leave a bad taste, stainless steel does not. Copper is used mostly just to line the bottom of the pan due to it's excellent heat conductivity.
Copper reacts with food, especially acid food which can actually leach a bit of copper out of the pan in the right conditions. Copper is also poisonous if you get too much, though apparently no one is sure how much is too much. Copper in paint for the bottoms of boats, or copper sheathing was used for a long time because marine life couldn't live on it. So the pans are lined with a non-reactive metal. That used to be tin, but is now usually stainless steel. Any copper pot or bowl without a lining should not be used for cooking or heating anything. A copper bowl, however, when used to beat egg whites, makes them hold more air.
