Microwave Cooking

Appears in
Oxford Companion to Food

By Alan Davidson

Published 2014

  • About

Microwave Cooking first saw the light of day in 1945 when an American engineer called Percy Spencer, found that a bar of chocolate in his pocket was softened by proximity to the magnetron, a British invention, on which he was working. The magnetron was central to radar technology (also British), and his employer the Raytheon Company was building radar sets as part of the war effort. Magnetrons emit microwaves which cause some molecules (particularly water molecules) to vibrate and therefore to heat. What is so remarkable is that water (and food which contains water) is heated, but other materials (for example, the food’s containers, or the oven itself) are not. And this heat is produced at a very low cost in energy. A magical technology, indeed, and one that Spencer and Raytheon were quick to explore. The first ovens were produced from 1947. They were called Radarange in a nod to their origins. However, they were large, heavy, and expensive and it was not until 1967 that an appliance suitable for domestic use was available. As the unit price dropped, and the technology became more foolproof, so the device’s popularity soared. By the end of the 20th century, more than 90 per cent of US households had a microwave, a figure matched in Britain by 2007.