The idea of making a soufflé seems to scare many home cooks. Or at least, that’s what I keep hearing, since it never really scared me. Perhaps it was watching “Good Eats” for years before ever actually cooking something, or because complicated recipes simply don’t scare me: they are simply a sequence of techniques and steps, carried out in a certain order, often in a time or temperature-dependent way. So too is a soufflé.
A savory (non-sweet) soufflé is at its very core nothing more than flour, butter, milk, eggs, and air. The addition of flavorful ingredients makes the soufflé tasty, such as the traditional Gruyere or Emmental in a cheese soufflé. A sweet soufflé includes the addition of sugar and a sweet flavor component, such as dark chocolate. A soufflé is constructed by creating a dense and highly flavored base, carefully incorporating beaten egg whites, then baking the batter in a straight-sided container in a hot oven. The soufflé expands and rises as it cooks, then inevitably deflates as it cools, preferably while being eaten.
A soufflé rises so miraculously for two reasons. The first was previously mentioned: air. As air is heated, it expands. Conversely, as air cools, it contracts or shrinks. This can be demonstrated with an empty, sealed water bottle and a freezer. Place an empty, sealed water bottle (the disposable kind, which have thin and flexible walls) into the freezer. Within an hour, the air will have cooled and contracted, causing the sides of the bottle to buckle inward. Taking the bottle out and allowing it to come to room temperature will cause the air to expand, forcing the bottle into it’s original shape. To see further expansion of the air within the bottle, place a small amount of very hot water in the bottle and give it a gentle shake (after carefully sealing it). The hot water will heat the surrounding air, resulting in expansion and putting pressure on the bottle. If the sides of the bottle do not significantly bend outwards, the increased pressure can still be observed by removing the cap, resulting in a hiss as warm air is forced out of the bottle.
Therefore incorporating air into a soufflé batter, then heating it in the oven, will cause the soufflé to rise. This is why beating the egg whites to “stiff peaks” is so important. Not only does this result in trapping air bubbles within the protein matrix of the egg whites (which is why beaten egg whites expand), stiffly beaten egg whites better captures the second expanding element in a soufflé: steam. Many of the components in a soufflé batter contain lots of water: eggs, milk, butter, etc. When water reaches 212°, it turns into steam and expands (Note: liquid water does not expand or contract based on temperature: it is non-compressible*. Water expands as it freezes into ice, or when it evaporates into steam.). The expanding steam causes the soufflé batter to rise, while the stiffly beaten egg whites capture and prevent the steam from escaping, helping the soufflé rise higher.
*Technically water is compressible, but just barely. For our purposes, it’s non-compressible.
Constructing a soufflé requires multiple steps, most of which involve creating the thick and flavorful base. A cheese soufflé requires the creation of a roux (cooking equal parts flour and butter), which is turned into a béchamel by adding milk and carefully simmer, then finally into a Mornay sauce by adding shredded cheese. Egg yolks are then beaten, tempered, and carefully added to the base. While time-consuming, the base of the soufflé can be made a few hours ahead of time, then gently warmed when you are ready to bake. The time-dependent steps involve beating and carefully incorporating the egg whites, followed immediately by baking and serving. To obtain the most rise, the egg whites must be beaten to stiff peaks, which can be aided by some form of acid (e.g. lemon juice or cream of tartar). Once stiff peaks are obtained, the egg whites are carefully “folded” into the base. This is distinct from “stirring”, because the objective is to incorporate the egg whites while maintaining as much of the foam structure as possible, as opposed to creating a homogenous and even mixture of the base and egg whites. It’s perfectly acceptable, if not the desired goal, if there are large streaks of egg whites left in the batter. The final step is adding the soufflé batter to a straight-sided dish and baking in a hot oven. The straight sides of the dish will help the soufflé rise by directing the steam and expanding air upwards. Coating the insides of the dish with a layer of butter, followed by a dusting of grated Parmesan cheese, will provide a rough surface for the batter to grab as it rises. It will also add to the crispy and delicious crust that forms on the sides and bottom of the dish.
Creating a crust on the top of the soufflé batter, before the temperature rises significantly, will also aid in the soufflé’s rise. Putting the uncooked soufflé under the broiler for a minute of two will achieve this. Applying heat directly to the bottom of the soufflé dish will also aid in the expansion of the soufflé batter. This can be achieved by baking the soufflé directly on the bottom of the oven, or by placing in on a heated pizza stone (provide enough time for the pizza stone to heat, 45min-1hr).
The beauty of the soufflé is that you can incorporate a wide array of flavors and ingredients into the dish, as long as they are cooked and relatively small (much like the versatility of a risotto). Soufflés also benefit greatly from an accompanying sauce (particularly sweet soufflés), but because they are inherent moist, a sauce is not required.
Upon request, I’m working on a chocolate soufflé recipe, which will be appearing soon. Until then, find your favorite soufflé recipe, and give it a try!