Chickflix has posted an Instructable that pierces the veil of mystery and describes how to mix your own Pop Rocks at home. The secret ingredient turns out to be pretty mundane, alas — I always assumed that they were filled with some violent, rare substance that ground its way through my guts on the way out. On the other hand, now that the secret is in the open, it paves the way for exotic Pop Rock flavors, such as French mustard, roast beef, and pineapple.
~ 2 Cups Sugar
~ 1 Tsp Baking Soda
~ 1/4 Cup Citric Acid Crystals (Can be tricky to find. If your local gourmet/country store doesn't have them, try here .)
~ 1/3 Cup of Corn Syrup
~ Small amount of Water (Just enough to get sugar wet)
~ 1/4-1 Tsp Flavoring (any extract will work. Use what you like! When using stronger flavors such as cinnamon, mint, and cherry, you can use a small amount (about 1/4 teaspoon). Subtler flavors such as lemon, strawberry, orange, and peach require more (1/2 to 1 teaspoon.)
~ A Few Drops of Food Coloring of your choice