In a large bowl, mix the baking soda, cornstarch, citric acid, buttermilk powder
mix until well combines, no hard lumps
add the essential oil to the carrier oil
pour over the dry ingredients and mix well. The oil will form clumps of powder, try to work them out to evenly distribute.
In a blender, blend the dehydrated fruit with a tablespoon of the bath bomb powder mix. Pour into a separate bowl
Spritz the bath bomb powder mix with rubbing alcohol, mixing quickly with your hand as you go. You don't want it to start fizzing.
Continue just until the powder can hold its shape. Don't over spray it, you don't want it getting very wet. Do the same for the fruit powder, just a tiny bit to help stick
To form your bath bombs: Pack the mold with the bath bomb mix.
You can add dried herbs, Sprinke in the fruit powders on top, in stripes or throughout.
Take the bath bomb out of the mold, and set it to dry. Ideally in a low-humid environment. Dry for 12-24 hours.
As long as it doesn't get wet, it will last for a long time! I would try to use it up within the next month, so that it's fresh and fizzy!