Ruhlman's Twenty (15 page)

IF YOU COULD CHOOSE TO MASTER A
single ingredient, no choice would teach you more about cooking than the egg. It is an end in itself; it’s a multipurpose ingredient; it’s an all-purpose garnish; it’s an invaluable tool. The egg teaches your hands finesse and delicacy. It helps your arms develop strength and stamina. It instructs in the way proteins behave in heat and in the powerful ways we can change food mechanically. It’s a lever for getting other foods to behave in great ways. Learn to take the egg to its many differing ends, and you’ve enlarged your culinary repertoire by a factor of ten.

You can cook eggs like a brute, and they’ll still be eggs, but eggs are best when handled with finesse. Finesse is refinement. Finesse is delicacy. Finesse requires deep thoughtfulness about what you’re cooking and what you’re attempting to achieve. Working with the egg teaches you these qualities and helps you strengthen them—in your hands, in your eyes, in your mind.

Furthermore, there’s no ingredient a cook can bring more honor to than the humble, ubiquitous egg. The egg is the perfect food—an inexpensive package dense with nutrients and exquisite flavor, a food that’s both easily and simply prepared and also virtually unmatched in terms of versatility in the kitchen.

Finally, the egg is meaningful simply as a beautiful object, the hard but delicate shell protecting the life within, its elliptical curves symbolic of life and fertility.

The egg is divine.

How do you improve as a cook when you attempt to understand the egg?

First, recognize the main principle of eggs: eggs require gentle heat and gradual temperature change. Certainly you can achieve interesting effects with sudden change using high heat (frying and deep-frying), but the egg is at its most versatile when gentle heat is put to it, whether you’re cooking a custard in a water bath, whipping yolks over simmering water, poaching eggs in hot water, and even frying eggs gently in butter (the water in the butter helps keep the temperature down).

Eggs go from fluid to solid when their proteins, all bundled up and separate from one another, uncoil via heat and lock together. The same thing happens when you cook a piece of meat. The proteins lock together and set up. Therefore, a squishy rare steak cooked to well-done becomes stiff and tough. This is why an egg white cooked at 145°F/63°C for an hour will be opaque yet very, very delicate and still partly fluid, but when hard-boiled, it will become rigid. When that transition happens fast in high heat, the proteins lock up too closely because of the heat and the water loss, becoming tough and dry. When the temperature change is gradual, so is their unwinding and leisurely hooking up, with plenty of water in the gaps. This is why custards are smooth and velvety when cooked in a water bath and why some chefs prefer their scrambled eggs cooked in a double boiler, because eggs scrambled this way are almost magically succulent. Gentle heat results in tenderness.

When you recognize this, you can begin to think more clearly and efficiently about cooking your eggs.

Since eggs like gradual temperature change rather than sudden, taking them out of the refrigerator a couple of hours before you intend to cook them would make sense. Doing so makes a little difference but is not critical. How do you cook an egg in its shell? You can drop it into boiling water, but you have more control by starting an egg in cold water and bringing it gradually up to temperature.

To hard-boil eggs, for instance, cover them generously with cold water in an appropriately sized pan (don’t cook a single egg in a giant
stockpot). Bring them to a complete boil, remove the pan from the heat, cover it, and let the hot water finish cooking them gently. For large eggs, I find that 15 minutes in hot water, followed by a good long chill in an ice bath to prevent the yolk from turning green and smelly, gives me a vivid yellow yolk that is completely cooked through. For all methods of cooking eggs in the shell, you should start timing the cooking at the point when the water reaches a complete boil. To cook soft-boiled eggs, rather than remove the pan from the heat once the water boils, reduce the heat to low and cook 1½ minutes for a true soft-boiled egg, one that’s very runny, 2½ minutes for an egg with a set white and a fluid yolk, or 3 minutes for a thickened but not solid yolk, sometimes called mollet (moh-LEH). But as with all matters that involve cooking, small variations result, in the end, from small variations at the beginning. The size of the egg and how cold it is can affect cooking times, so it’s best to pay attention to your own eggs and how you use them. Keep track of how long it takes to get them the way you like them. Then write it down so you don’t forget.

The next most important idea to recognize and embrace is the power of a cooked egg to transform a dish: the supreme power of the egg as garnish. Many dishes are improved by the addition of an egg. A salad becomes a meal when you put an egg on it. Cooked asparagus spears are a welcome side dish; put a poached egg on top, and they become a main dish. Raw or lightly cooked egg yolk is a ready-made sauce. An egg poached in tomato sauce transforms that sauce into a main course (serve it on a piece of toasted bread with a side of sautéed spinach). A steak or burger, a sandwich, a pizza, a soup, a stew—every category of dish is transformed by the addition of an egg. Put another way, if you have an egg and one other ingredient, a last-minute meal can be moments away.

The third thing to understand is the egg’s impact on texture: the egg as tool. An egg white is an extraordinary leavener when whipped to peaks. An egg yolk is a powerful emulsifier that keeps microscopic orbs of oil separate so we have mayonnaise rather than cooking oil, Hollandaise sauce rather than melted butter. A custard made with whole eggs is firmer and shinier than a custard made with yolks only. Compare the texture of a crème caramel, a custard made with whole eggs, and a crème brûlée, a custard made with just yolks. The former is sliceable, while the latter is set but creamy. One has egg whites, and the other does not.

And that is all, or the beginning at least, of understanding the egg.

The custard is a subcategory of egg cooking that, like the egg itself, is so versatile that understanding the way it works and what it can do will expand your range in the kitchen exponentially. We tend to think of custards as being sweet, but savory and salty custards are terrific starters or side dishes.
Bread pudding
is nothing more than bread that has soaked up a custard. Any cream soup can become a custard—just add eggs and serve at the same point in the meal with a crunchy garnish. A quiche is one of the most delicious savory custards known to humankind. A
cheesecake
is a custard enriched with cream cheese and sour cream. Vanilla sauce, sometimes called crème anglaise, is a custard you can pour; freeze it, and it becomes ice cream. A famous drink is simply a loose custard: eggnog. Some kinds of cake icings are custards. Expand the boundaries of your thinking, and you see that the cake itself is a custard to which flour has been added.

To keep considerations of the custard grounded, let’s break it into three main forms:
whole-egg custards, yolk-only custards, and pourable custards.

Whole-egg custards, such as the crème caramel and the quiche, can stand alone as custards you can slice. The basic rule is that 1 large egg will set ¾ cup/180 milliliters of liquid to a very delicate consistency.

I prefer a little more stability in a stand-alone custard, along with additional richness, and use 1 large egg per ½ cup/120 milliliters of liquid. For a basic vanilla custard in the manner of the crème caramel, the proportions are 4 large eggs and 2 cups/480 milliliters combined milk and cream, plus sugar and flavoring. Omit the sugar, add salt and a little nutmeg, and pour the custard in a high-sided crust filled with bacon and onion, and you have quiche. Pour it over bread, and you have bread pudding. Because all these dishes are sliced when served or are meant to stand alone on a plate, they need the structure provided by the proteins in egg whites.

These custards and others such as crème caramel and Spanish flan are best cooked in a water bath to ensure that their texture remains smooth and delicate. Even cheesecake benefits from being cooked in a water bath; the gentle heating will prevent the rapid expansions and contractions of air responsible for large fissures in the surface. For custards that have lots of interior flavorings, such as a quiche, or are primarily garnish, such as bread pudding, a water bath is not necessary.

Yolk-only custards are my favorite for their unparalleled richness and depth of flavor and their deeply satisfying, voluptuous texture. Crème brûlée is the classic incarnation of the all-yolk custard. Classic lemon curds are yolk-based custards that set when cooled. These custards can be taken in a savory direction with the addition of, say, roasted red pepper or caramelized onion, and served to accompany something very lean such grilled/barbecued fish or a vegetable salad.

Pourable custards are variants of the yolk-only custard. The yolks are cooked over direct heat or over heated water until thick but still pourable. The result is a custard sauce or vanilla sauce. As with other custards, pourable custards can be transformed into rich sauces for savory foods. You might make a lemony, salty sauce for a meaty fish such as salmon or monk fish, or add tarragon, shallot, and black pepper to a sauce for grilled steak. Butter, not milk and cream, is typically used for sauces such as hollandaise or béarnaise. These classic sauces are essentially custard sauces made with butter instead of cream.

If you like to experiment with food, nothing is more fun than messing around with eggs, and one of the best things to mess with is the egg white. The ability of this combination of proteins and water to trap air is its most dramatic use. Other, more subtle uses, such as the impact of the egg white on a cocktail or its ability to give solidity to a fish or chicken purée, should not be overlooked.

The primary characteristic to know about an egg white is that it has two components: a thin watery part and a thick cohesive part. The thin watery part is what swirls away when you poach an egg (it doesn’t matter how much vinegar you put in the water, a common practice I don’t recommend). To avoid the unsightly flurry of loose egg white in poaching water, Harold McGee, an authority on the science of cooking, suggests pouring the egg into a large slotted spoon to allow the loose white to fall off, leaving only the viscous part of the white and, as a result, a prettier poached egg. It’s a great technique.

By far the most important characteristic of the egg white is its ability to become foam. As a foam, it brings air to food. Normally we wouldn’t think that the addition of air would enhance a dish, but such is the importance of texture. A bread that has risen is a pleasure to eat; one that has not is nearly inedible. Cakes are defined in large measure by their soft, airy crumb. A cake without air is not a cake; it’s a biscuit. One of the best ways to achieve an airy cake is to separate the yolks, beat the whites to soft peaks, and fold them into the batter. Batters to be fried can be lightened in the same way. The chief attribute of a soufflé is airiness. The dish is named for the French to breathe. Cakes and soufflés rise in the oven because the air bubbles trapped by the egg white expand. They fall because the air bubbles contract as they get cooler.

Foamed egg whites are used in many other ways, savory and sweet. Whipped with sugar, they become meringues. Raw meringue often tops a lemon curd for lemon meringue pie. The same meringue can be baked in a very low oven, just to dehydrate it, for crunchy meringues. Or it can be poached or cooked in a water bath to become the French preparation called floating islands. If you add a little flour to a meringue and bake it, you will have an angel food cake.

Egg whites demonstrate that by understanding the properties of an ingredient, of half an ingredient, you can improve as a cook in numerous directions.

The recipes in this chapter address the ways that eggs can be cooked and used (the egg as leavener is discussed further in
technique #9, Batter
). They are grouped into three categories:

• Scrambled Eggs with Goat Cheese and Chives
  
• Shirred Eggs with Cream and Parmigiano-Reggiano
  
• Classic New York Cheesecake
  

• Pizza Bianco with Bacon and Eggs
  

• Mayonnaise
  
• Aioli
  
• Cheddar Cheese Soufflé
  
• Savory Bread Pudding with Caramelized Onions and Gruyère
  
• The VTR Whiskey Sour