Popping candy (also called space dust or pop rocks) was popular in the early 1980s until rumours spread around the world that eating space dust and drinking cola was causing kids to explode (not true by the way, we’ve tried).
The small pieces of hard candy are made primarily of boiled sugar syrup that contains tiny bubbles of pressurised carbon dioxide. When you eat them the saliva in your mouth melts the sweets and releases the carbon dioxide, creating a fizzing sensation and that crackling sound.
You can prolong the candy popping by coating in a fat or oil eg. Chocolate or a praline paste or melted butter this will give it a protective briar to the candy and only activate when the Chocolate is melted (eaten).
Popping candy is very sensitive to humidity (it loses its gas and goes flat) and Moisture in the Atmosphere over a period of time, So keep the lid on and in a cool dry place when not using.
The bubbles are freed from the candy and burst on your tongue and in your mouth.
Like candy and caramel, the Popping candy melts when it comes in contact with water or your saliva (but not with oil or fat).