The foundation of the bath bomb is a simple chemical reaction between an acid and a base - it this case, citric acid and baking soda. You could make bath bombs with just those two ingredients and a bit of water. They wouldn't be very exciting...but they'd sure fizz really well in the bath!
The recipe I use has a few more ingredients and adds a bit of luxury to the bath. (And why else do we take the time to relax in the bath if not for a bit of luxury!?)
So clean off the counter, and let's get going.
For a video version of these instructions, check out my How to Make Bath Bombs video.