Since some foods are acidic and can react with copper or even corrode it, we decided to tin some of our cookware.
This way you will be able to cook acid food without having to worry about your health and you can leave food inside it for a while after you cook it, contrarily to what happens with copper utensils.
Also, tin is the closest metal to match copper in thermal conductivity, so your tinned cookware will heat up very quickly. But bear in mind that tin melts at 231ºC, so you should never use strong fire for long periods of time.