3Cooking PrinciplesBecause 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.
4ContinuedScorching-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.
5Preparing 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.
6Preparing 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.
7Cheese Cheese is a concentrated form of milk. To make cheese, milk is coagulated-the curd (solid part) is separated from the whey(liquid part)
8Cooking with CheeseLike 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.
10EmulsifiersMixture that forms when you combine liquids that ordinarily do not mixExample:10
11Thickeners Heat causes the protein in eggs to coagulate (thicken) Eggs can be used alone as the thickening agent or used with starchExample:11
12Binding AgentsHold together ingredients in foods that normally would not stick together.Example: Meatloaf12
13Interfering AgentsIce cream and sherbet stay creamy because of the eggs in themEggs prevent the formation of ice crystals.Example:13
14Egg FoamsCreated by adding air to food by beating and whipping14
15Factors Affecting Egg Foams Temperatureseparate easily when coldcan be beaten to max. volume when at room temperaturelet stand at room temperature for 30 minutes before beatingBeating TimeCan be underbeaten or overbeatenFat and Fat containing ingredientsEgg yolk will inhibit formation of foamUse glass or metal bowl and clean beatersAcidMakes egg whites more stable…. Example is cream of tarterSugarIncreases stabilityIncreases beating time…add when foam has reached most of its volume15
16Stage 1FoamyBubbles and foam on the surface…mixture will flow out of bowl when tilted16
17Stage 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 tip17
18Stage 3 Stiff peaks Full volume White and shiny When you lift the beaters, peaks will stand up straight18
20Stages of Foam Formation Foamy: small bubblesSoft: looks white, moist, shiny peaks that fold overStiff: peaks stand uprightDry: gone too far, breaks down & looks curdledFrom PowerPoint Presentation tool for Understanding Food, 1 edition by Reprinted with permission of Wadsworth, an imprint of the WadsworthGroup, a division of Thompson Learning
21SoufflesFigure 13-10The main ingredients of a soufflé are a thick base generally made from a white sauce or pastry cream, an egg white foam, and flavoring ingredientsWhite sauce: A mixture of flour, milk, and usually fat.Stiffly beaten egg whites are folded into the thick egg yolk mixture.A soufflé is actually a modified omelet.The soufflé originated in France. Soufflé literally mean “puff.” Heat causes expansion of air in foam.BULLET 2 – To fold, place a mixing utensil in the center of the mixture, move the utensil in a downward stroke, then across the bowl, & then come bring the utensil back up. Move bowl in a circular motion during the folding process. Folding helps to prevent overcoagulation of the protein.Place in ungreased glass cup or baking dish, so soufflé can cling to sides.Due to the heat of the oven, there is expansion of air in foam causing the soufflé to rise (puff). Baking in a water bath will help to decrease the chances of overcoagulation of the outer edges. You will bake your soufflé in a water bath. A water bath consists of placing the souffle mixture in a baking dish and then placing the dish in a pan of water.
24Dry Heat Moist heat Preparation of Eggs Fried Scrambled omelets “Boiled” eggsCoddled eggs prepared in a cupPoached eggsA variety of custardsEggs that are prepared using the microwavePrime (season): To seal the pores of a pan’s metal surface with a layer of heated-on oil.“Boiled” not the correct term. Should use “cooked”Hot-Start Method: Soft: 3 to 4 minutes,Medium: 5 to 7 minutes Hard: 12 to 15 minutesCold-Start Method: Soft: 1 minute,Medium: 3 to 5 minutes,Hard: 10 minutesEggs cook extremely rapidly in a microwave oven.Special caution should be taken to avoid overcooking.Whole eggs with intact shells should never be microwaved.Steam expanding within the shell can cause them to burst.The same principle applies to whole eggs out of the shell.Egg yolks will burst if not punctured with a toothpick or the tip of a knife prior to going into the microwave.
25Double Boiler: Water placed inside the bottom pan prevents direct heat and avoids scorching +=You will use a double boiler in your lab to make stirred custards. Using a double boiler decreases the chances of overheating your product and thus decreases the chances for curdling, syneresis and overcoagulation of the protein. When you make your stirred custard, you will pour the egg mixture into the top of the double boiler and then place this in the bottom of the boiler that will be filled with simmering water…pretty cool, huh?