Cooking with Dairy and Eggs Cooking Principles of Dairy Cooking Principles Because milk is protein food, special care must be taken during cooking to prevent the following: Scum Formation-a solid layer that often forms on the surface of milk during heating. To prevent scum formation, stir the milk during heating and cover the pan. Boiling over-usually caused by scum formation. Use low heat to prevent. Continued Scorching-burning that results in a color change. To prevent, use low heat. Curdling-high temperature, acids, tannins, enzymes and salts cause the milk proteins to coagulate and cause clumps. Use a low temperature and fresh milk to prevent. Preparing Common Milk Based Foods White Sauce-starch thickened milk product. Classic White Sauce is prepared with a roux- a cooked paste of flour and fat. Melt 1 part fat over low heat. Stir in 1 part flour to form a roux. Stir in milk. Stir constantly as you cook the mixture over medium heat until it thickens into a smooth sauce. You can use a slurry (a liquid mixture of milk and flour) to thicken a white sauce. Preparing Other Sauces and Gravy To make a cheese sauce, stir grated cheese into a basic white sauce after it has thickened. To make gravy-juices from meat are used in place of some or all the milk to give gravy flavor. Cheese Cheese is a concentrated form of milk. To make cheese, milk is coagulated-the curd (solid part) is separated from the whey(liquid part) Cooking with Cheese Like all high protein foods, heat can adversely affect cheese. If you cook cheese at too high of a temperature, the cheese will become rubbery and tough. Objective 7.05 Emulsifiers Mixture that forms when you combine liquids that ordinarily do not mix Example: Thickeners Heat causes the protein in eggs to coagulate (thicken) Eggs can be used alone as the thickening agent or used with starch Example: Binding Agents Hold together ingredients in foods that normally would not stick together. Example: Meatloaf Interfering Agents Ice cream and sherbet stay creamy because of the eggs in them Eggs prevent the formation of ice crystals. Example: Egg Foams Created by adding air to food by beating and whipping Factors Affecting Egg Foams Temperature separate easily when cold can be beaten to max. volume when at room temperature let stand at room temperature for 30 minutes before beating Beating Time Can be underbeaten or overbeaten Fat and Fat containing ingredients Egg yolk will inhibit formation of foam Use glass or metal bowl and clean beaters Acid Makes egg whites more stable…. Example is cream of tarter Sugar Increases stability Increases beating time…add when foam has reached most of its volume Stage 1 Foamy Bubbles and foam on the surface…mixture will flow out of bowl when tilted Stage 2 Soft peaks Have reached full volume Look white and shiny When you lift beaters out of foam, foam will stand in peaks that curl over at the tip Stage 3 Stiff peaks Full volume White and shiny When you lift the beaters, peaks will stand up straight STAGES OF FOAM FORMATION From PowerPoint Presentation tool for Understanding Food, 1 edition by 2000. Reprinted with permission of Wadsworth, an imprint of the WadsworthGroup, a division of Thompson SOUFFLES The main ingredients of a soufflé are a thick base generally made from a white sauce or pastry cream, an egg white foam, and flavoring ingredients White sauce: A mixture of flour, milk, and usually fat. Stiffly beaten egg whites are folded into the thick egg yolk mixture. Figure 13-10 PREPARATION OF EGGS Dry Heat Fried Scrambled omelets Moist heat “Boiled” eggs Coddled eggs prepared in a cup Poached eggs A variety of custards Eggs that are prepared using the microwave DOUBLE BOILER: WATER PLACED INSIDE THE BOTTOM PAN PREVENTS DIRECT HEAT AND AVOIDS SCORCHING + =