The History of the Microwave Oven

Microwave ovens have become one of the most common kitchen appliances in the world. From the best microwave oven in India to the United States, microwaves are ubiquitous. The history of the microwave is more interesting than you might expect. Early models were available in the 40s for upwards of $3,000 and looked more like refrigerators than the small boxes we see today.

The History of the Microwave Oven

An Accident of Birth

Like many other appliances and gadgets, the microwave oven didn’t come from a desire to make household chores more efficient.

The modern microwave began life in 1940 when John Randall and Harry Boot invented the cavity magnetron tube at the British Birmingham University. The magnetron tube was vital for use in the Second World War and helped the Allied Forces emit microwave radar signals to spot aircraft and ships in the distance.

American engineer Percy Spencer was conducting maintenance work on a live radar in 1945. The engineer felt a tingling sensation across his body and noticed a chocolate bar in his pocket melted. After a bit of work, Spencer deduced that the chocolate was softened by the microwaves emitted by the magnetron tube. The microwaves heated the bar up and melted it.

Percy Spencer continued to experiment with the tube by aiming it at kernels of corn. The experiment had the desired effect, and Spencer effectively invented microwave popcorn. Spencer then built a metal box with an opening on the front and a magnetron tube poking into the side. He used the box to heat a variety of foods, including his lunch. One of his more notable experiments was attempting to microwave an egg. Anyone who has tried that at home won’t be surprised to hear that the egg exploded all over the face of one of his colleagues. It was thanks to this accident that he got the idea to put a door on the prototype microwave.

Perry Spencer filed his patent for the microwave – U.S. Patent 2495429 A – in October 1945. The patent details how to cook food using microwaves. The description for the patent includes examples of Spencer cooking a potato and egg in the microwave using a fraction of the energy used for traditional cooking methods at the time.

The Early Microwave

The original microwaves made and sold in the 40s were mammoth beasts compared to what we have today. Microwaves were first sold in 1947 by American defense firm Raytheon. Raytheon sold the RadaRange of microwaves for $5,000. Accounting for inflation, that would be over $50,000 by today’s standards. The RadaRange microwave was nearly six feet tall, weighed more than one-third of a tonne, and pumped 3,000 watts of power through its circuits. The original models were unfit for wide domestic use. These microwaves were made for ships, canteens, and restaurants.

The microwave slowly shrank in size, and a counter-top version was available in 1967. The counter-top version was sold by Amana and retailed for $495, over $3,000 in today’s money.

The Modern Microwave

Litton developed the modern microwave that we know and love. The new short and wide microwave was a near-instant hit, selling tens of thousands of units in 1970 and millions of units by 1975. Technological improvements and cheaper electrical parts meant that microwaves could become smaller, more practical, and more affordable by the end of the 1970s. By 1986, 1 in 4 American households had a microwave. The U.S Bureau of Labor Statistics reported that nearly every American – 9 in 10 – owned a microwave by 1997.

The modern microwave follows the short and wide format created in the 70s. Even so, there are plenty of different types of microwave ovens available today. Microwaves come in all shapes, sizes, and colors, including models that stand over a stove. Modern microwaves are also more functional than their ancestors. Microwaves these days can grill and steam food as well as microwave it. You’d be amazed at what your microwave can cook if you gave it a chance. Think about that simple accident of a melted chocolate bar the next time you bite down on delicious microwave food – and think where we’d be without it.