Oven Shopper

Reviews and General Buying Information on
Microwaves, Toasters, Convection Ovens and More

How a Microwave Oven Works

This page of my website is dedicated to those of you who have a more, shall we say, technical interest in microwaves and how they work. It’s also dedicated to people who are just curious about how it’s possible for you to put some food into what is essentially a metal box, hit a button (or turn a dial) and hey presto! Your meal is ready!

There is a reason why microwaves are called this and that’s because they use “micro-waves” to cook food or heat liquids. Now, I’m no technician. I’m just someone who was looking for a new microwave and became very interested in what’s “out there” so in the following few words, I aim to explain how a microwave oven works in simple terms.

A Little Bit of History on the Magnetron

The magnetron (which every microwave has) is where it all happens, and in fact it’s how microwaves were born thanks to a man by the name of Percy Spencer who was a system engineer. He was actually testing this device in order to help develop radar systems for military use in the mid 1940’s.

What happened is pretty amazing really. When testing the magnetron Mr. Spencer had an odd tingling sensation and then he discovered the chocolate bar in his pocket had miraculously melted! Curious about this, he put some popcorn in front of the device and to his amazement that cooked as well. He also tried a raw egg which cooked. Well, it exploded actually AND in his colleagues face!

That, my friends is how the microwave came about but how does it actually work?

How You Get Tasty Well Cooked Food Fast!

Radio waves are what help to cook or reheat food and liquids and as we all know there is a good deal of water in food. When the “waves” reach a certain frequency which is usually around 2.5 GHz the water molecules begin to get “excited”. When this happens heat is produced and that spreads from the water molecules to all other parts of the food.

Once everything get’s going your food begins to cook and because of the technology used it happens much faster than in a conventional oven. In a conventional oven, heat has to penetrate food from the outside in whereas microwaves do the opposite.

You may now be wondering why the containers you use in a microwave oven don’t cook. Well, (and I think this is very clever) the radio waves pass straight through materials like glass, ceramic or plastic without having any effect on them at all. However, metal is a different story.

If you’ve ever accidentally (or out of curiosity) put foil or a metal container in a microwave you will know what can happen. It will start to spark and in more serious cases cause a good deal of damage to your microwave (and even you)! This is because metal reflects the radio-waves used by microwaves hence the light show!

If you’re interested in finding out more about how a microwave oven works and want to hear the facts from an expert, feel free to take a look the following video I found just for you.

Back to Top