In a large bowl, combine your dry ingredients - Epsom salt, baking soda, cornstarch and citric acid. Mix very well with a whisk, for about 2-3 minutes.

In a small jar with lid, add the wet ingredients - olive oil, water, essential oil and soap colorant. Place the lid on the jar and shake very well, until all of the wet ingredients are completely mixed together.

Add the liquid mixture to the dry mixture very slowly. It is important to add just a few drops at a time, while continuously whisking the mixture. The mixture may start to fizz if you do not so this step slowly enough, while mixing it in right away. This will cause the bath bombs to expand in the mold and not form right.

After all liquid has been poured and stirred in, mix very well until the color is consistent and you do not have large clumps.

Fill each of the molds with the bath bomb mixture, firmly stuffing each side full.

Secure both parts of the mold together, give a quick twist to get any excess mixture out, and let set for about 24 hours. This gives the bath bomb plenty of time to form.

To release, twist one half of bath bomb mold. If it’s not releasing well, grab a spoon and lightly tap the half of bath bomb mold. This should do the trick. Repeat with the other half to fully release bath bomb.