Mix the dry ingredients first (Epsom salt, baking soda, cornstarch and citric acid), using your whisk- whisk until there is no clumps found.
- Pour the wet ingredients (grapeseed oil, water and food coloring and  essential oil(if adding) into your mason jar, close the lid and shake well.
- Very slowly add the liquid mixture to the dry mixture, about a few drops at a time, while whisking.
NOTE: If you’re not pouring slowly enough, the mixture will start to fizz and you don’t want that to happen.
- Once all of the liquid has been poured into the dry mixture, mix very well until the color is consistent.
- Immediately fill the molds with the mixture, firmly stuffing each side full as possible.
- Secure both parts of the mold together and let set.
- Let sit for over 24 days or a full day to be on the safe side
- Carefully release bath bombs from molds and put into an airtight container, or individual cello bags.