In the previous post, we gave you some tips for whipping egg whites to perfection. We strongly advised using a copper bowl. In this post, we're going to tell you why a copper bowl works best.
When egg whites are whisked in a copper bowl (and remember, they need to be whisked by hand, not mixed with an electric mixer, for best results), the copper ions in the bowl migrate into the egg whites themselves to form a molecular bond with an egg protein known as conalbumin.
This conalbumin/copper molecular complex is far more stable than the molecular complex of whipped egg whites alone. The result is that egg whites whipped in a copper bowl are far less likely to "unfold" than those whipped in a stainless steel, or any other type, of bowl.
The difference can truly be dramatic and we hope you'll try it.