What are Pop Rocks, and how are they made?
Pop rocks are hard candy mixed with carbon dioxide gas at a high pressure, so that it forms microscopic high-pressure bubbles inside it. As the candy melts in your mouth, it releases the compressed tiny bubbles with a “pop”. What you feel and hear are these 600-psi tiny bubbles of carbon dioxide compressed gas exploding as the candy melts in your mouth. Pop rocks are made just like your basic candy: Combine sugar, corn syrup, water and flavoring; heat at 300 degrees until the water evaporates; and you are left with pure syrup which hardens into candy when it cools. But the difference is that the hot syrup is mixed with carbon dioxide gas at about 600 pounds per square inch (psi), causing tiny 600-psi bubbles to form in the candy. After it cools, release the pressure. The candy will shatter, but the shattered pieces will still contain the high-pressure bubbles. Keep in mind that this process is patented.