Reader Clay writes:
I’ve whipped whole eggs to a pretty impressive volume, which is why I’ve always been skeptical of the claim that fat ruins foams.
True enough, Clay. However while whole eggs will make foams, they’ll never rise as high or last as long as all-white foams. Under the right conditions egg whites can be whipped up to about 8 times their original volume. With whole eggs you’re doing well if you can do 3 times, and even then the foam will only hold up for a few minutes on its own. However a whole egg foam will last long enough to be of some use in a thing like a flourless cake, where you want to lighten the consistency just enough to prevent it from baking up into a chocolate brick. Though I suppose even a brick can be good if it’s made of chocolate, yes?.