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Microwaves

Microwaves. How long have microwaves been around?.

peter-gibson
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Microwaves

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  1. Microwaves

  2. How long have microwaves been around? • 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!

  3. Diagram of Microwave

  4. How Does a Microwave Work? • The microwave oven generates electromagnetic waves (called microwaves) which makes water move. This motion leads to friction, and friction leads to heating. Motion Friction Heat

  5. 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.

  6. What are the advantages of having a microwave? • Faster • Retains Nutrients • Tastes Better • Defrost Meat • Softens brown sugar (Put 1C. of water in microwave) • Plumps Raisins • Freshens snacks and chips • Eliminates extra oils and fats in preparing foods • Made a impacted on today’s lifestyle and cooking habits • Cook’s food quickly with high quality

  7. What are microwaves attracted to? • Fat • Sugar • Water Molecules

  8. Acceptable dishes for the microwave • Glass • Paper • Plastic • Microwaveable Dishes

  9. Unacceptable Dishes • Metal • Dishes with gold or silver on it

  10. Acceptable Coverings • Paper Towels- to absorb moisture, spatters, and spills • Wax Paper- Holds in some of the moisture • Plastic Wrap- holds in moistures

  11. Foods that should not be microwaved • Eggs in a shell • Pancakes-they don’t get a crust on them. • Canning foods -does not get high enough temperature or have enough pressure. • Deep-fry foods- fat can not be controlled • Large amounts of food- Takes to long, not as efficient

  12. Techniques • Stirring: To pull heated part of the food to the center. • Turning Over: To microwave all sides. • Standing time: To allow the foods to complete its cooking (place directly on counter). • Shielding: Small pieces • Covering: • A: Retains nutrients • B. Holds in moisture • C. Speeds up cooking

  13. Arrange food in circular shape: to make cooking even • Rotating: Makes cooking even • Pricking: (egg yolks and potatoes) to keep from exploding. • Select foods of the same size: cooks evenly

  14. Do round or square containers cook more evenly? Round Square

  15. Burns • To prevent • Food can create hot containers • Items can explode (egg, potatoes). Pierce them with fork. • Lifting the cover or plastic from the food can cause a burn. • Hot steam escaping can cause a burn.

  16. Cooking Tips • When cooking in the microwave, the volume of the food (small versus large potatoes); and the quantity or number will increase cooking and standing time. • Standing time at the end of cooking allows for foods to continue to cook when removed.

  17. Superheating • http://www.phys.unsw.edu.au/~jw/superheating.html • http://www.colorado.edu/physics/2000/microwaves/index.html • Learning how microwaves works.

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