An Accidental Oven.

Today, October 8th …

The enduring story about the invention of the microwave oven is that it happened as a result of an accidental discovery in the presence of a superior mind. The story says that in 1945 a self-taught engineer called Percy Spencer working for a company called Raytheon was standing in front of a large operational magnetron, found that the chocolate bar in his pocket had melted, deduced that this was due to the microwaves being emitted from the machine, and rushed away and invented the oven.

Parts of this story are true. Spencer had no formal education beyond high-school. He was working with magnetrons. He does seem to have been the victim of a melted candy bar in the pocket at some stage. Most of the rest of the story is a result of the apparent human desire to have a single hero to solve every problem, rather than an unromantic committee. The problem was not how to cook your porridge directly in your bowl, thereby avoiding the disgusting thing that is a porridge saucepan with complimentary residual porridge remnants. The problem was what to do with all the industry infrastructure when the war ended and radar equipment (which is where the magnetrons were being used) was no longer needed.

Those working in the industry had been aware for a long time of the heat produced by the microwave radiation – it is said that workers used to take advantage of it to warm their hands on cold nights. With the war effort winding down, a lot of creative thinking went into considering how the magnetron-radar industry might be turned to peace-time use. As we saw in a recent post, it was the same incentive that led the manufacturers of Saran to come up with ways of converting military into domestic plastic. Spencer (who already had 120 patents to his credit) had been intrigued for some time by the possibilities of using microwaves for cooking, and led some experiments in this direction.

Fine minds spurred on by the problem of the bottom line finally came up with the goods, and on this day in 1945 Raytheon filed a patent for a microwave cooking process. The first commercial oven was produced in 1947. It was a monster measuring almost 6 feet (1.8m) tall, weighed in at 750 pounds (340 kg) and required a hefty cooling system – hardly suitable for the kitchen bench. It was twenty years before domestic models started to become popular, and even now the idea keeps getting tweaked – we are promised (it may already be, I am not a microwave expert) models which will recognise the barcode on a pack of processed food, retrieve the necessary information, and cook the meal accordingly.

In the early days back in the factory, the story says that after the melted candy bar incident, Spencer experimented with a few other foods, the next two being popcorn (very successful) and egg (not successful to the colleague who leaned to close and got a face-full of exploding egg.) The microwave oven is still a popular way to cook popcorn. The Aztecs were popping corn several millenia ago, but true to form, humans have been tweaking the idea ever since. One tweak led to Popcorn Balls, which became very popular in the second half of the nineteenth century.

Popcorn Balls.
Boil honey, maple, or other sugar to the great thread; pop corn and stick the corn together in balls with the candy.
[Housekeeper's Encyclopedia of useful information … E.F. Haskell, 1861]

Popcorn Balls.
One cup of molasses, one cup of brown sugar, one tablespoon of vinegar, butter size of an egg. Boil all ingredients until brittle. Pour this over two quarts of popcorn and mold into balls.
[The Neighborhood Cook Book … Council Of Jewish Women. 1914]

Tomorrow’s Story …

The Last Blackberries.

Quotation for the Day …

Cookbooks bear the same relation to real books that microwave food bears to your grandmother's. Andrei Codrescu.