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Microwaves. How does a microwave work???. History of Microwaves. In 1945, Dr. Perry Spencer, a scientist, was working in a lab when he felt some heat on his hand.
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Microwaves How does a microwave work???
History of Microwaves • In 1945, Dr. Perry Spencer, a scientist, was working in a lab when he felt some heat on his hand. • The heat was coming from microwaves. These were being emitted from a nearby vacuum tube. Dr. Spencer was curious and place a chocolate bar near the tube. • Within seconds, the chocolate melted. That sticky mess was the beginning of a brilliant idea – the microwave!
How Does a Microwave Work? • The microwave oven generates electromagneticwaves (called microwaves) which makes water move. This motion leads to friction, and friction leads to heating. friction heating motion
How Does a Microwave Work? • This heat starts on the outside of the food and moves in. • The denser the food the longer it will take to cook. • Water will heat faster than a burrito, because a burrito is more dense than water.
Microwaves • Microwaves are attracted to foods that are high in: sugar fat water
Microwave-able Containers • Paper • Plastic • Glass • Microwaveable Dishes
Non-Microwave-able Containers • Metal • Dishes with gold or silver on it. • If you’re unsure, check the label on the dishware.
Acceptable coverings for microwave dishes: • Paper towel – to absorb moisture, spatters, and spills. • Wax paper – holds in some of the moisture • Plastic wrap – hold in moisture
Techniques for Microwaving • Stirring: To pull heated part of the food to the center • Turning over: To microwave all sides • Rotating: Makes cooking even • Pricking: To keep foods from exploding • Standing Time: To allow foods to complete its cooking by placing on the counter.
Cooking Time • These will increase the cooking time and standing time: • The volume of the food • Example: Small potatoes versus large potatoes • The quantity or number of food
Microwave Safety • To prevent burning yourself from microwave cooking, remember: • Foods can create hot containers…Use Pot Holders • Items with an unbroken outer “skin” can explode. Pierce them with a fork. • Items with an unbroken outer “skin” potatoes, hot dogs, apples, sausages, chicken livers, etc. • Lifting the cover or plastic from the food can cause a burn. • Hot steam escaping can cause a burn
Cooking Controls Time FeaturesConvenience Features Time Cook Amount of cooking time Starts Immediately (1,2,3,4) Starts Immediately (1 or 2) Food Type 1-4 Time Defrost Amount of defrost time Popcorn Beverage Reheat Power Level Add 30 Sec Power Level 1-10 Starts Immediately Cook Food Type (1-6) Express Cook Starts Immediately 1 2 3 Auto Defrost Food type & Weight 4 5 6 Kitchen Timer
Cooking Controls Time Cook Time Defrost • Microwave for any time up to 99 minutes. • Press time cook • Enter cooking time • Change power level if needed • Press start • Defrost for a selected length of time. • Press Time Defrost • Enter defrosting time • Press start
Cooking Controls • Press Time Cook OR Time Defrost • Enter cooking or defrosting time • Press Power Level • Select Desired power level 1-10 • Press start • Each power level gives you microwave energy a certain % of the time. • Power level 7 = 70% • Power level 10 = 100% • Lower settings cook more evenly & need less stirring or rotating. • Higher settings cook faster Power Level
Potato Lab • How to cook a potato in the microwave • How to make Cheese Sauce on the stove top
Microwave Potato Lab • Baked Potatoes- ½ potato per person. You will share with a person in your group! • Prick a well-scrubbed potato several times with fork tines. • Microwave on HIGH for 6 to 8 minutes, using 100 percent power. • Turn the potato over and rearrange. Cook for additional 6 to 8 minutes until done. Wrap in foil. • Let stand 5 to 8 minutes to finish cooking. • Broccoli • Wash, cut and chop broccoli into bite-size pieces. • Put in a glass pie plate with saran wrap. • Add 1-2 tablespoons of water. • Cover with saran wrap. • Cook on HIGH for 3-5 minutes or until tender crisp and done. Place in a small bowl. Let stand, keep covered, for 5 minutes. • Drain any excess water and mix with the cheese sauce.
Microwave Potato Lab • Cheese Sauce • 2 tbs. butter • 2 tbs. plus 1 tsp. flour • Dash pepper • 1 ¼ cup milk • 1 ¼ cup grated cheese • In a pot, melt butter • Gradually, stir in flour and pepper. Mix with a wisk • Continue until the mixture is smooth. • Add milk all at once. Stir until combined. • Cook, uncovered, on HIGH for 3 to 5 minutes or until thickened and bubbly; stirring until the sauce starts to thicken. • Stir every 30 seconds. • Add 1 ¼ cup grated cheese and stir until the cheese is melted. • Then pour over the cooked broccoli and serve on top of the potato.
Are microwaves Dangers? • Video Clip