Uses of Eggs

EGGS AS THICKENERS: A sauce or custard can be thickened, called coagulation, by adding egg and heating, critical to many recipes. A large portion of the discussion of stirred and baked custard hinges on egg coagulation. In many instances, the egg in a recipe will serve to glue the ingredient's together. When eggs are added to a mixture to thicken, sometimes the mixture is quite warm. If added directly, the mixture will cook the eggs. A technique called tempering is used when combining the two to avoid this problem.

EGGS AS BINDERS: Whole raw egg adds moisture to a mixture and holds the ingredients together. As the food is heated, egg protein coagulates, thus binding ingredients together. This is a very useful property for binding in products such as meat loaves, formed meat and poultry products and for natural thickening of custards and pie fillings. The temperature of coagulation can be controlled by adjusting pH, adding salts and other ingredients.

EGGS AS GLAZES: Egg whites, egg yolks, whole eggs, and egg washes brushed on breads and other baked products add a rich, shiny glaze. The glaze is caused primarily by the protein and fat interaction. The simple glaze is generally made by adding a "little water" to the egg and brushing it on.

EGGS AS LEAVENERS: Eggs serve as leaveners in their ability to foam. Egg whites or egg yolks can each foam separately or together as a whole egg. Whisking egg white incorporates air and produces a foam - a relatively stable mass of bubbles. Whole eggs incorporate air less well, especially when beaten into a batter, but give a sponge cakes a light texture. If left to stand, egg white foam will gradually collapse, but when heated the foam becomes permanent, such as meringue. The Angel Food Cake, a white cake, tall and light in texture, is leavened only by beaten egg whites. Before the invention of the egg beater, making this heavenly delight required a deep platter, a whisk and a very strong arm for whipping the egg whites. The electric mixer has simplified the process. I use my handheld mixer for whipping small amounts and my stand mixer, fitted with a whipping attachment, for larger amounts. Make sure the egg whites reach at least 1/3 of the way up the beaters. If not, use a hand-held one.

EGGS AS CLARIFIERS: Eggs and egg whites have been used as a clarifier. The process is as it sounds, the clearing of a liquid. Master chefs use it to clarify stock to produce clear consommés.

EGGS AS EMULSIFIERS: Eggs and gelatin are among the foods that contain emulsifiers. Egg yolk contains lecithin which acts a an emulsifier. Adding egg yolk to a mixture of oil and water prevents the two liquids from separating; the emulsifiers in the yolks are liaisons between the two liquids and serve to stabilize the mixture. Emulsifying is done by slowly adding one ingredient to another while simultaneously mixing rapidly. This disperses and suspends tiny droplets of one liquid through another. However, the two liquids would quickly separate again if an emulsifier were not added. An example of this is mayonnaise which is an emulsion of oil and vinegar, held together by egg yolk. Industrially manufactured mayonnaise uses pasteurized egg (which has been heat treated to destroy potentially harmful micro-organisms), rather than raw egg, to ensure safety.

EGGS ADD COLOR AND FLAVOR: The yellow color of egg yolk derives from the fat-soluble carotenoids in the lipid portion of lipoproteins. This rich color means quality and the anticipation of good flavor in such recipes as pasta, mayonnaise and cakes. Over a hundred volatile components contribute to the flavor of eggs. Egg flavor provides a rich, rounded, neutral background against which other flavors can be highlighted. The flavor is delicate enough that it blends well with most ingredients.

EGGS ENABLE COATING such as breadcrumbs to stick to the surface a product and forms a protective barrier during cooking.