Quick Fact: How Microwave Cooking Works

Quick Fact: How Microwave Cooking Works

[Picture Source]

Although cooking in the microwave oven is similar to cooking in conventional oven, microwaves penetrate food much faster and deeper. They do not cook the food from the inside (common misconception), neither do they cook it directly. What they do is affecting the water molecules from within with little effect on other molecules like protein, fat, carbohydrates, etc. The microwave radiation penetrates the food evenly throughout, and heats up the water which then cooks the food. Because some food contains more water inside than outside (pastry or pies with filling, potatoes, etc.), it can give an impression that it starts cooking the food from within its centre. When a product contains evenly spread amount of water, the water on the surface is cooked first as it swallows up the most of the microwaves. That's why it is difficult to use microwave oven for cooking the food that contains little amount of water like dry food. Because the water boils at 100°C (usually), the temperature never gets beyond that point. The conventional oven requires much higher temperature over 200°C that breaks down sugars and proteins giving the food its specific crust.

[Picture Source]

The microwaves are part of the spectrum of electromagnetic radiation that has wavelengths shorter than radio waves but longer than infrared light. The first microwave oven was invented by American physicist Percy Spencer. While experimenting with microwave magnetron (high density electromagnetic field generator) that was designed for use in military radars, he discovered that the candy bar in his pocket had melted. He later experimented with various sorts of food including popcorn (first microwave popcorn) or egg (which exploded in the face of his co-worker). In 1945, he patented the first, safe for use, microwave oven called Radarange that included magnetron which emitted microwaves into an enclosed metal box. Two years later, in 1947, the first commercial microwave oven was manufactured.

[Some of the first commercial Radarange. Picture Source]

References:

"Microwave Oven", Wikipedia article.

"Percy Spencer", Wikipedia article.

"Microwave", Wikipedia article.

-logic