Salt

Salt increases the whipping time and decreases the foam’s stability. Salt crystals dissolve into positively charged sodium and negatively charged chloride ions, and these probably compete for bonding sites on the unfolded protein molecules, thereby reducing the number of protein-protein bonds and so weakening the overall structure. It’s therefore best to add salt to the other components of a dish—the base of a soufflé, for example— rather than to the foam itself.