Question: I received a copper bowl for a wedding gift. What can I do with it?
A copper bowl is not just a bit of useless fanciness for the kitchen. The real reason you use a copper bowl is for egg whites. Copper strengthens the proteins of egg whites for more lift and stability. Remember to use a big balloon whisk since this is about getting air into those whites.
It will also be good for making zabaione, the Italian custard with Marsala wine, sugar and eggs. Don't cook anything else in copper since the reactions with some chemicals can be toxic.
When it comes to copper bowls, bigger is better -- egg whites expand to four times their original size when beaten.
Clean and polish the bowl before and after usage with a mixture of vinegar and salt, rinse with hot water and dry thoroughly. Whites won't rise if any fat is present -- vinegar and salt take care of that.