Microwave ovens as we have come to know them today first became popular around about the 1970's, and they revolutionised the way food was cooked and reheated for ever. The first ever microwave oven in 1953 was five feet high and was patented by an American engineer called Percy Spencer who had made his discovery by accident, he was working with a radar system that used a magnetron to send out radiowaves when a chocolate bar he had in his pocket simply melted rather too quickly. He went on to develop his idea further and hey presto.



A normal oven cooks a lot slower by cooking the outside first whereas a microwave oven cooks the food from the inside first and cooks through to the outside afterwards. I shall try to explain the many facets of microwaves including how they work and why they work.

Using radiowaves is a much quicker method of cooking as it vibrates water, fat and sugar molecules together causing heat to build up and it is this action that actually cooks your food. Made up from several parts starting with a metal box there is a generator inside the metal box which is known as a magnetron, which uses electricity to put out waves which are channelled onto your food which is usually on a rotating turntable to produce a more even cooking pattern. When the waves hit your food they don't just ricochet off they pass right through the food substance, and as they pass through they penetrate your food and heat it up by causing the rapid vibration of the tiny molecules.

Before this marvellous invention they were really only two ways to cook food on a conventional oven, by conduction or convection. Convection is easily explained by imagining you are cooking a pot of soup on a hob plate of an oven, your soup is hotter at the base of the pot closest to the heat. As the hot soup rises cold soup is pushed down onto the bottom of the pot thus moving the soup in a continually rising and falling motion called convection heating.

Secondly conduction heat is explained by imagining cooking a turkey inside a normal oven, heat is generated by a gas source or an electric source (usually hot metal bars) the heat travels toward the turkey by radiation and touches the surface of the turkey and slowly heats it up from the outside in, you also get hot air very near the surface of the turkey which evaporates moisture on the surface which is why ovens create a crispy coating on most oven roasted food stuffs.

To get a crispy coating from a micro waved meal you need to trap the heat generated with another material which is usually a foil & cardboard combination sleeve this gets very hot and allows the food to create a crust which if you've ever micro waved a pastry product you will understand what I mean. Nearly everybody knows or soon learns that you don't try to place anything metal inside your home microwave as it will destroy the cavity of the oven with a pretty light show of sparks and flashes. Commercial microwaves are much more powerful than the domestic variety and can range from 1000 watts of cooking power all they way up to around 2000 Watts and usually come supplied without a turntable.