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I'm Christian Sager and this is brain Stuff. There's lots of urban legends about pop rocks, candy like they supposedly explode if you eat them with soda, and the kid who played Mikey in those eighties Life Cereal commercials died from combining the two. Have you ever heard those? Neither of them are true. But here's one that was actually reported in a nineteen seventy nine issue of Newsweek. A shipment of pop rocks overheated in a delivery truck and
blew its doors open. If that's true, how did it happen, And for that matter, how do pop rocks work? Anyway? We know they are a candy that you put in your mouth, triggering carbonation, a tiny burst, and a popping sound. They were invented in nineteen fifty six by William A. Mitchell when he was trying to create instant soda crystals
that melted in water. Mitchell was working for General Foods at the time, but before that he worked in an agricultural experiment station in Lincoln, Nebraska, where get this, he blew his lab up and it left him with burns all over most of his body. Yeah, it's true. Even after that disaster, Mitchell still formulated a candy with potentially volatile properties. Here's his basic recipe as it was refined in nineteen eighty. All hard candies are made from a
combination of sugar, corn syrup, water, and flavoring. With Pop Rocks, you heat these ingredients to dissolve the sugars and additives. Then you boil the mixture, evaporating most of the water at atmospheric pressure. What's left is a pure sugar syrup. Here's where pop rocks unique recipe differs from other hard candies. Before cooling, the sugar remixture is gasified and combined with carbon dioxide at six hundred pounds per square inch. This takes about two to six minutes and forms bubbles in
the candy. Lower temperatures make larger bubbles and produce a better pop. When the pressure is released in the candy cools, it shatters into pieces full of these trapped bubbles of gas. When you put a piece of this candy in your mouth, it melts and the gas escapes, causing the short popping sensation. Those pops are the sound of six hundred p s i worth of carbon dioxide being released from each bubble. P s i is a unit of pressure where one
pound per square inch of force is exerted. Before pop rocks leave the factory, they're examined by a testing panel train to evaluate the popping sensation on a scale from zero to fourteen. Zero represents no popping and fourteen represents maximum popping. Anything lower than a seven is rejected as inadequate. Ratings between seven and nine generate a satisfactory pop, while anything between ten to twelve is considered outstanding because they
pop louder. But what about the delivery truck in nineteen seventy nine where the doors blew open. Well, pop rocks shouldn't be stored at over eighty five degrees fahrenheit or they'll melt and pop in the package, So the combined release of all that carbon dioxide is what opened the truck's doors. All that stuff about soda explosions and Mikey dying is just a myth, though, but that didn't stop it from having a major effect on pop rocks reputation.
General Foods actually had to arrange a telephone hotline at one point for anxious parents. They even sent Mitchell out on a tour to debunk the rumors. There's all kinds of variations on the ledgend. Check out the brainstuff channel on YouTube, and for more on this and thousands of other topics, visit how stuff works dot com