the outset, in order to obtain a very firm, dense foam A Silver Bullet for the Copper Theory Why copper bowls make more stable egg foams? I’ve wondered about this for many years In 1984 I did some experiments with the help of Stanford University biologists, and then published a theory in the British science journal Nature and in the first edition of this book The experiments suggested that one of the albumen proteins, ovotransferrin, takes up copper from the bowl surface and is thereby rendered resistant to unfolding — which could make the foam as a whole resistant to overcoagulating That theory stood up for ten years, until one day on a whim I tried whipping egg whites in a silver-plated bowl Ovotransferrin doesn’t bind silver, so the foam should have turned grainy It didn’t It remained light and glossy I resumed my frothy investigations, and learned that both copper and silver do block sulfur reactions between proteins Hence the revised edition of the copper theory outlined here Water Water is seldom called for, but in small amounts it increases the volume and lightness of the foam Because water thins the whites, however, it’s more likely that some liquid will drain from the foam Albumen diluted by 40% or more of its volume in water cannot produce a stable foam Basic Egg-Beating Techniques Beating egg whites into a foam is one of those techniques about which cooks and cookbooks wax stern and stringent In fact it’s not all that sensitive to details Just about any egg and bowl and whisk can give you a good foam Choosing the Eggs An egg foam begins with ... I resumed my frothy investigations, and learned that both copper and silver do block sulfur reactions between proteins Hence the revised edition of the copper theory outlined here Water Water is seldom called for, but in... small amounts it increases the volume and lightness of the foam Because water thins the whites, however, it’s more likely that some liquid will drain from the foam Albumen diluted by 40% or more of its volume in water... Beating egg whites into a foam is one of those techniques about which cooks and cookbooks wax stern and stringent In fact it’s not all that sensitive to details Just about any egg and bowl and whisk can give you a good foam