Utensils

The best bowl for whipping egg whites is one that is made of stainless steel or copper. Its shape should be deep, and it should have sloping sides and a round bottom. The whisk you use should be in proportion to your bowl.

Plastic bowls are difficult to keep grease-free, glass bowls are slippery, and aluminum bowls may release small particles of metal when you whisk, graying the foam.

The only difference I can see between stainless steel and copper bowls is that the egg whites cling to the copper more. Some pastry chefs feel the copper reacts with the whites, lowering their pH (increasing their acidity), thereby strengthening their air-trapping ability and making it easier for the whites to stretch and expand. After lots of experimenting with both, my results were the same: I got close to 1 cup of foam per egg white. It was slightly faster and easier to whip in the copper bowl, but both foams looked the same after they had been whipped.