Beaten egg whites make soufflés rise and lighten up batters. Before beating egg whites, make sure that your mixing bowl and beaters are clean and dry. The whites won’t beat stiff if there’s even a speck of dirt, oil, or egg yolk in the bowl (or in the whites).
Place the egg whites in a large bowl.
Avoid using a plastic bowl. Fat and grease adhere to plastic, which can diminish the volume of the beaten whites. A copper bowl works best for beating egg whites.
Beat the whites slowly until they’re foamy.
If you’re using a mixer, use its lowest setting.
Increase your mixer’s speed to incorporate as much air as possible until the whites form smooth, shiny peaks.
If you use a whisk, the same principle applies — you just get an arm workout as an added bonus!
If you’re making a sweet soufflé, start beating in the sugar after the whites form soft peaks.
Continue beating until the sugar is incorporated in the whites.