Air is what enables us to achieve that iconic "puffy" soufflé. Well, air and the proteins in the egg whites which are the basis of every soufflé. This method is easy enough for the beginner home chef, a lesson in turning something as simple as an egg into something as magnificent as the soufflé. It is beaten eggs that give the structure and puff or leavening to any soufflé recipe. The motion of beating egg whites traps air into the mix. When baked, air bubbles in the egg whites expand. This expansion puffs the soufflé up over the top of the dish.