Copper bowls are one of the best pieces of cookware you can buy. Not only do they look great, but they also prevent egg deflation. When the egg is placed in a stainless steel or glass bowl, air expands eight times, stretching the protein in the egg. This causes the foam to form and lose its shape. The air does not expand with a copper bowl, and the omelet stays fluffy.
While copper is an excellent material for cooking, the thickness of the bowl is essential.