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Speaker 1: slash brain Stuff. Welcome to brain Stuff from How Stuff Works. Hey,
Speaker 1: I'm Christian Sager and this is brain Stuff. There's lots
Speaker 1: of urban legends about pop rocks, candy like they supposedly
Speaker 1: explode if you eat them with soda, and the kid
Speaker 1: who played Mikey in those eighties Life Cereal commercials died
Speaker 1: from combining the two. Have you ever heard those? Neither
Speaker 1: of them are true. But here's one that was actually
Speaker 1: reported in a nineteen seventy nine issue of Newsweek. A
Speaker 1: shipment of pop rocks overheated in a delivery truck and
Speaker 1: blew its doors open. If that's true, how did it happen,
Speaker 1: And for that matter, how do pop rocks work? Anyway?
Speaker 1: We know they are a candy that you put in
Speaker 1: your mouth, triggering carbonation, a tiny burst, and a popping sound.
Speaker 1: They were invented in nineteen fifty six by William A.
Speaker 1: Mitchell when he was trying to create instant soda crystals
Speaker 1: that melted in water. Mitchell was working for General Foods
Speaker 1: at the time, but before that he worked in an
Speaker 1: agricultural experiment station in Lincoln, Nebraska, where get this, he
Speaker 1: blew his lab up and it left him with burns
Speaker 1: all over most of his body. Yeah, it's true. Even
Speaker 1: after that disaster, Mitchell still formulated a candy with potentially
Speaker 1: volatile properties. Here's his basic recipe as it was refined
Speaker 1: in nineteen eighty. All hard candies are made from a
Speaker 1: combination of sugar, corn syrup, water, and flavoring. With Pop Rocks,
Speaker 1: you heat these ingredients to dissolve the sugars and additives.
Speaker 1: Then you boil the mixture, evaporating most of the water
Speaker 1: at atmospheric pressure. What's left is a pure sugar syrup.
Speaker 1: Here's where pop rocks unique recipe differs from other hard candies.
Speaker 1: Before cooling, the sugar remixture is gasified and combined with
Speaker 1: carbon dioxide at six hundred pounds per square inch. This
Speaker 1: takes about two to six minutes and forms bubbles in
Speaker 1: the candy. Lower temperatures make larger bubbles and produce a
Speaker 1: better pop. When the pressure is released in the candy cools,
Speaker 1: it shatters into pieces full of these trapped bubbles of gas.
Speaker 1: When you put a piece of this candy in your mouth,
Speaker 1: it melts and the gas escapes, causing the short popping sensation.
Speaker 1: Those pops are the sound of six hundred p s
Speaker 1: i worth of carbon dioxide being released from each bubble.
Speaker 1: P s i is a unit of pressure where one
Speaker 1: pound per square inch of force is exerted. Before pop
Speaker 1: rocks leave the factory, they're examined by a testing panel
Speaker 1: train to evaluate the popping sensation on a scale from
Speaker 1: zero to fourteen. Zero represents no popping and fourteen represents
Speaker 1: maximum popping. Anything lower than a seven is rejected as inadequate.
Speaker 1: Ratings between seven and nine generate a satisfactory pop, while
Speaker 1: anything between ten to twelve is considered outstanding because they
Speaker 1: pop louder. But what about the delivery truck in nineteen
Speaker 1: seventy nine where the doors blew open. Well, pop rocks
Speaker 1: shouldn't be stored at over eighty five degrees fahrenheit or
Speaker 1: they'll melt and pop in the package, So the combined
Speaker 1: release of all that carbon dioxide is what opened the
Speaker 1: truck's doors. All that stuff about soda explosions and Mikey
Speaker 1: dying is just a myth, though, but that didn't stop
Speaker 1: it from having a major effect on pop rocks reputation.
Speaker 1: General Foods actually had to arrange a telephone hotline at
Speaker 1: one point for anxious parents. They even sent Mitchell out
Speaker 1: on a tour to debunk the rumors. There's all kinds
Speaker 1: of variations on the ledgend. Check out the brainstuff channel
Speaker 1: on YouTube, and for more on this and thousands of
Speaker 1: other topics, visit how stuff works dot com