The Speed of Microwaves

How Microwaves Work

• Microwave ovens use the power of microwave radiation, which is on the spectrum of electromagnetic radiation along with x-rays, radio waves and visible light. Magnetic waves fall in the 2.5 Gigahertz (Ghz) frequency, which is below the range of visible light and infrared radiation. The magnetron generates the microwave radiation that is then bounced around the inside of the oven using a metal fan. Microwaves cause the water molecules in food to vibrate rapidly; the resulting friction heats and cooks your meal.

Wattage

• The amount of electricity per second used by the magnetron to produce microwaves is measured in watts. The more watts used, the more microwave energy is generated by the magnetron and transferred to your food at a time. The wattage rating on a microwave is several hundred to over a thousand watts which indicates the amount of power transferred from the magnetron to the food. Depending on the efficiency of the specific magnetron, it may pull as much as twice the wattage from the outlet as is transferred to the food.

Convection

• Convection microwaves add another fan that distributes the air throughout the oven, allowing the food to cook from the internal heating of the microwaves and the external heating of the air circulating around the food. Convective heat promotes crisping and browning on the surface of the food, while the friction heat caused by microwaves produces steaming and moistness. Together they provide a result closer to traditional oven cooking in just a fraction of the time.

Speed

• In general, the higher the wattage of a microwave, the faster it will cook, and the addition of convection will speed cooking time as well. Most microwave recipes assume a 700-watt microwave, which will boil one cup (8 ounces) of water in two minutes and 30 seconds. A 1000-watt microwave will do the same job in a minute 45 seconds. Microwave ovens with a rotating tray and convection fan will increase the speed of cooking as well, though not as predictably as wattage.