Contributing Author: Gentle Heron
To understand how to safely cook food (and even heat water) in a microwave oven, it helps to understand a little about how they work. Microwaves are a form of radio waves that easily penetrate most materials, including food. These waves vibrate at a specific set of frequencies designed to agitate water molecules. All food contains water, to lesser or greater extent. When the water molecules in food are agitated, they vibrate, creating heat.
One of the advantages you’ll hear about microwave cooking is that it heats food faster than it can heat up in a conventional oven. This is true. The heat radiation in a regular oven must penetrate foods from the outside toward the center. This can sometimes leave the outside of food overheated or burnt while the center is undercooked or raw. Not so in a microwave, where the radiation penetrates immediately to the very center. This means all portions of the food, exterior and interior, cook at the same rate.
Another advantage of microwave cooking is that it does not heat the container. That’s because ceramics, glass and plastic do not contain water. Therefore there’s nothing in them to heat up in a microwave. In a regular oven, the food container also has to be heated up, making for a longer cooking time.
Then why do the dishes microwave food is cooked in sometimes feel hot? That’s heat warming them up from the hot food they contain. Always use oven mitts when handling containers of food that has been microwaved.
OK, if microwaves are so good at penetrating materials, why doesn’t the radiation escape from the microwave box and heat you up as you stand next to it? That’s because this type of radiation does not penetrate metal; it is reflected by it. The body of the microwave oven and its door is designed to contain the microwaves so none escape into the kitchen. If the door does not close and seal properly, or the body of the microwave is damaged in any way, do not use it. Replace or repair it.
You also will not want to use metal containers in the microwave. Also, be sure to check that any plastic, glass or ceramic container you intend to cook in is rated for microwave use.
Something you may not know: plain water can get overheated and explode in the microwave, or worse, in your face when you retrieve the cup. The easy way to avoid this is to either add the instant coffee or teabag or sugar before heating the water in the microwave, or if you’re not heating the water for a beverage, put a wooden spoon or stir stick in the container with the water. These simple steps will totally eliminate the small chance of overheating the water.
As with an electrical device, be sure you read and understand the manufacturer’s instructions and cautions before you use your microwave.
For an explanation of how microwave ovens work:
For an explanation of “superheated water” in a microwave: http://www.snopes.com/science/microwave.asp
Image credit: La_Petite_Femme, Pixabay