HOW BEATEN EGG WHITES WORK: When you whip egg whites (albumen), you are really stretching the protein
in them. As a result, they unwind and join together loosely, making them unstable. The liquid albumen forms elastic films
around the air bubbles beaten into them and essentially trap them, which you can see as a foam.
When the foam is heated, the trapped, tiny air cells expand from the heat of the oven and/or carbon dioxide released from
baking soda or baking powder, if used, causing a batter to rise. During baking, the egg protein coagulates around them,
giving permanence to the foam.
Sometimes whipped egg whites are the sole source of leavening in a recipe and is responsible for the structure of
soufflés, angel food cake, puffy omelets and meringue.
EGG WHITE TIPS: (How to separate eggs) Properly beaten eggs whites are fluffy and you can even hear the air
bubbles popping in them (that's why its good to use them right away in a recipe so they don't get a chance to
deflate). Room temperature egg whites whip best, which is done with a mixer or by hand with a wire balloon whisk.
Whipping egg whites are much like blowing air into a balloon -- you can do it right and get a fully blown balloon, or do it
too much, causing it to pop. If either occurs, you won't get a good volume and thus, they won't rise significantly in the
mixing bowl. The whipped egg whites will also have a thick and grainy texture. Unfortunately, if it happens, you have to
start again with a new batch of room temperature egg whites.
Fat
A trace of fat in the egg whites will greatly reduce their volume when whipped. Also, make sure the egg
beaters, bowl, and spatula are free of grease.
Weather & Temperature
To get the highest egg whites, whip room temperature egg whites, not cold ones; it's because the egg's protein
is more elastic and will create more tiny air bubbles. Also, the colder their temperature, the longer the beating
time will be. If it is humid or raining outside, sometimes you won't get the proper volume no matter what you do.
Acid (Cream of Tartar, Lemon Juice & Vinegar)
Cream of Tartar, a mildly acid salt made from grapes and containing tartic acid. It keeps the foam supple and elastic, but
stable, so it can expand to its fullest when baked. Cream of tartar isn't easily found in all parts of the country--so you can
substitute it.
Adding a small amount of acid, such as cream of tartar, lemon juice or vinegar, stabilizes egg whites and allows them to
reach their full volume and stiffness. It does this by making the egg coagulate faster. For example, angelfood cake egg
white foam has lemon juice or cream of tartar added as a stabilizer. The natural acid on the surface of a copper bowl
achieves the same result, so don't add ANY acidic ingredient when using.
Salt
Salt enhances flavors and is added even for sweet soufflés. It also helps to make the whites beat more easily, but some
feel decreases the foam's stability. Some bakers recommend adding it with the raw egg whites at the beginning of
whipping while others say to add it along with other dry ingredients, or to the yolks, if possible.
Sugar
Egg whites beaten without sugar will not peak as firmly as those with sugar.
Sugar also serves as a whipping aid to stabilize beaten egg foams, which are essentially a delicate protein network. Sugar
pulls the water from the structure and allows it to set better. Meringue made from beaten egg whites and sugar, can sit
longer and hold their shape than foams without sugar. If a whipped egg white recipe does not include sugar, and the egg
whites will eventually be folded into a base, I recommend adding in a couple of tablespoons of white sugar, taken from the
recipe; a small amount will stabilize the whipped whites.
Manipulation
Beating, stirring and jarring can break down the foam. When you fold them in, use a gentle touch.
Time
Use your whites immediately upon beating them. If they sit for more than 5 minutes, they start to deflate, so whip
again by hand with a whisk, if they do. They will keep a bit longer if the foam contains sugar or an acid, such as cream of
tartar.
Rubber Spatula
A large rubber spatula is great for folding ingredients together