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There's lots 23 00:01:19,680 --> 00:01:23,600 Speaker 1: of urban legends about pop rocks, candy like they supposedly 24 00:01:23,760 --> 00:01:26,480 Speaker 1: explode if you eat them with soda, and the kid 25 00:01:26,600 --> 00:01:30,760 Speaker 1: who played Mikey in those eighties Life Cereal commercials died 26 00:01:30,880 --> 00:01:34,000 Speaker 1: from combining the two. Have you ever heard those? Neither 27 00:01:34,040 --> 00:01:36,960 Speaker 1: of them are true. But here's one that was actually 28 00:01:37,000 --> 00:01:41,000 Speaker 1: reported in a nineteen seventy nine issue of Newsweek. A 29 00:01:41,080 --> 00:01:45,000 Speaker 1: shipment of pop rocks overheated in a delivery truck and 30 00:01:45,160 --> 00:01:49,640 Speaker 1: blew its doors open. If that's true, how did it happen, 31 00:01:49,920 --> 00:01:53,600 Speaker 1: And for that matter, how do pop rocks work? Anyway? 32 00:01:54,000 --> 00:01:55,800 Speaker 1: We know they are a candy that you put in 33 00:01:55,840 --> 00:01:59,840 Speaker 1: your mouth, triggering carbonation, a tiny burst, and a popping sound. 34 00:02:00,320 --> 00:02:03,720 Speaker 1: They were invented in nineteen fifty six by William A. 35 00:02:03,920 --> 00:02:07,320 Speaker 1: Mitchell when he was trying to create instant soda crystals 36 00:02:07,320 --> 00:02:10,720 Speaker 1: that melted in water. Mitchell was working for General Foods 37 00:02:10,760 --> 00:02:13,280 Speaker 1: at the time, but before that he worked in an 38 00:02:13,280 --> 00:02:18,280 Speaker 1: agricultural experiment station in Lincoln, Nebraska, where get this, he 39 00:02:18,440 --> 00:02:21,040 Speaker 1: blew his lab up and it left him with burns 40 00:02:21,120 --> 00:02:24,360 Speaker 1: all over most of his body. Yeah, it's true. Even 41 00:02:24,440 --> 00:02:29,480 Speaker 1: after that disaster, Mitchell still formulated a candy with potentially 42 00:02:29,600 --> 00:02:33,760 Speaker 1: volatile properties. Here's his basic recipe as it was refined 43 00:02:33,840 --> 00:02:36,800 Speaker 1: in nineteen eighty. All hard candies are made from a 44 00:02:36,840 --> 00:02:41,680 Speaker 1: combination of sugar, corn syrup, water, and flavoring. With Pop Rocks, 45 00:02:41,800 --> 00:02:45,200 Speaker 1: you heat these ingredients to dissolve the sugars and additives. 46 00:02:45,520 --> 00:02:48,360 Speaker 1: Then you boil the mixture, evaporating most of the water 47 00:02:48,480 --> 00:02:53,160 Speaker 1: at atmospheric pressure. What's left is a pure sugar syrup. 48 00:02:53,720 --> 00:02:57,920 Speaker 1: Here's where pop rocks unique recipe differs from other hard candies. 49 00:02:58,280 --> 00:03:02,720 Speaker 1: Before cooling, the sugar remixture is gasified and combined with 50 00:03:02,840 --> 00:03:07,760 Speaker 1: carbon dioxide at six hundred pounds per square inch. This 51 00:03:07,840 --> 00:03:11,840 Speaker 1: takes about two to six minutes and forms bubbles in 52 00:03:11,880 --> 00:03:15,960 Speaker 1: the candy. Lower temperatures make larger bubbles and produce a 53 00:03:16,040 --> 00:03:20,160 Speaker 1: better pop. When the pressure is released in the candy cools, 54 00:03:20,320 --> 00:03:24,520 Speaker 1: it shatters into pieces full of these trapped bubbles of gas. 55 00:03:24,960 --> 00:03:27,080 Speaker 1: When you put a piece of this candy in your mouth, 56 00:03:27,320 --> 00:03:32,079 Speaker 1: it melts and the gas escapes, causing the short popping sensation. 57 00:03:32,560 --> 00:03:35,840 Speaker 1: Those pops are the sound of six hundred p s 58 00:03:35,920 --> 00:03:40,720 Speaker 1: i worth of carbon dioxide being released from each bubble. 59 00:03:41,400 --> 00:03:44,200 Speaker 1: P s i is a unit of pressure where one 60 00:03:44,280 --> 00:03:48,520 Speaker 1: pound per square inch of force is exerted. Before pop 61 00:03:48,600 --> 00:03:51,920 Speaker 1: rocks leave the factory, they're examined by a testing panel 62 00:03:52,240 --> 00:03:55,760 Speaker 1: train to evaluate the popping sensation on a scale from 63 00:03:55,880 --> 00:04:01,640 Speaker 1: zero to fourteen. Zero represents no popping and fourteen represents 64 00:04:01,960 --> 00:04:06,760 Speaker 1: maximum popping. Anything lower than a seven is rejected as inadequate. 65 00:04:07,320 --> 00:04:11,200 Speaker 1: Ratings between seven and nine generate a satisfactory pop, while 66 00:04:11,240 --> 00:04:15,960 Speaker 1: anything between ten to twelve is considered outstanding because they 67 00:04:16,000 --> 00:04:19,480 Speaker 1: pop louder. But what about the delivery truck in nineteen 68 00:04:19,600 --> 00:04:22,960 Speaker 1: seventy nine where the doors blew open. Well, pop rocks 69 00:04:22,960 --> 00:04:26,240 Speaker 1: shouldn't be stored at over eighty five degrees fahrenheit or 70 00:04:26,279 --> 00:04:29,760 Speaker 1: they'll melt and pop in the package, So the combined 71 00:04:29,760 --> 00:04:32,920 Speaker 1: release of all that carbon dioxide is what opened the 72 00:04:32,960 --> 00:04:37,080 Speaker 1: truck's doors. All that stuff about soda explosions and Mikey 73 00:04:37,160 --> 00:04:40,159 Speaker 1: dying is just a myth, though, but that didn't stop 74 00:04:40,200 --> 00:04:43,479 Speaker 1: it from having a major effect on pop rocks reputation. 75 00:04:44,040 --> 00:04:48,120 Speaker 1: General Foods actually had to arrange a telephone hotline at 76 00:04:48,160 --> 00:04:52,400 Speaker 1: one point for anxious parents. They even sent Mitchell out 77 00:04:52,440 --> 00:04:55,919 Speaker 1: on a tour to debunk the rumors. There's all kinds 78 00:04:55,960 --> 00:05:03,760 Speaker 1: of variations on the ledgend. Check out the brainstuff channel 79 00:05:03,760 --> 00:05:05,919 Speaker 1: on YouTube, and for more on this and thousands of 80 00:05:05,920 --> 00:05:21,680 Speaker 1: other topics, visit how stuff works dot com