Hot Pocket: History of the Microwave

Find out how a melted chocolate bar sparked the microwave revolution.

When our microwave oven failed last year, my 9-year-old daughter wailed, “How will we eat?” Her reaction demonstrates how indispensible this culinary convenience has become to the modern kitchen — a development the man credited with its invention probably couldn’t have imagined.

The roots of microwave oven technology go back to World War II, when scientists used the magnetron, an electronic tube that produces extremely short radio waves (microwaves), to enhance British radar systems. After the war, magnetron manufacturer Raytheon was looking for ways to adapt its profitable technology to the private sector. According to legend, Raytheon engineer Percy Spencer was testing a magnetron when he noticed the candy bar in his pocket melting. This led to experiments with popcorn (which popped) and an egg (which also popped, supposedly in the face of a coworker).

Seeking to harness the device’s cooking power, Spencer and his colleagues began rigging up prototypes — reportedly even attaching a magnetron to a galvanized garbage can — and eventually created a metal box that contained the microwaves and rapidly heated food. Spencer filed a patent for his “Method of Treating Foodstuffs” in 1945 and envisioned a conveyor belt for ushering food into the device. In the following three years he also filed patents for using microwaves to cook popcorn and lobsters. But hot dogs were the first microwaved food available to the masses, thanks to the installation of Speedy Weeny vending machines at various locations including New York’s Grand Central Terminal in 1947.

That same year, Raytheon produced the first commercially available microwave oven. Named the Radarange (the winning submission in an employee contest), it stood nearly 6 ft. tall, weighed 750 pounds, cost about $5,000 (or $51,000 today) and required a 220-volt electrical line and plumbing for the water-cooled system. Marketed for restaurants, large ships, hospitals, etc., the appliance was a slow seller. Raytheon subsequently licensed its microwave technology to Tappan, which introduced a 220-volt home wall unit priced at $1,295 in 1955 ($11,000 today).

Ten years later, Raytheon bought Amana and developed a home countertop microwave priced at $495 ($3,400) in 1967. It ran on 115-volt current and featured two buttons (“start” and “light”) and two control knobs: one for cooking times up to five minutes; the other for times up to 25 minutes. Amana launched an intense media campaign to promote the ovens in Chicago: Specially trained home economists helped consumers install their new microwave and cook their first meal; these experts and service technicians (guaranteed to arrive within one hour) remained on call for the first year.

Despite initial fears that microwaves could cause radiation poisoning, blindness, sterility and impotence, the appetite for quick eats grew voracious. More manufacturers entered the market (Litton is responsible for introducing the modern short, wide oven configuration), and as the technology evolved, prices decreased. By 1976, more kitchens boasted microwave ovens than dishwashers.

Besides making cooking easier at home, microwave technology radiated into various industries, not just for food service but also for roasting peanuts and coffee beans, shucking oysters and drying potato chips, leather, textiles, paper, ceramics, cork, match heads, pencils, flowers and more. Inspired by (and possibly facilitating) the movement of more mothers into the workforce, it has led to the development of easy-to-nuke snacks and meals and greatly influenced kitchen design. What started as a major wall-unit investment and later shrank to a relatively cheap countertop contraption has come full-circle, with (DIY-friendly) built-in units installed over the range to provide ventilation as well as a mouthwatering menu of food-prep functions, from defrosting meat to popping corn, roasting hot dogs and of course, melting chocolate.

Photographed at a demonstration in April 1947, the Radarange (shown above) could cook a hamburger in 15 seconds and half of a small fresh chicken in four minutes.

Want more?
Check out History of the Adirondack Chair.
History of the Dishwasher.