Wearing a mask, preferably a 3-Ply Safety mask, gently and slowly pour the SLSA into the mixing bowl holding the baking soda and citric acid. Use a whisk to gently combine these ingredients. Try to avoid the airborne powder rising from the bowl. 

Add coconut oil and butter of choice to a heatsafe bowl or jug and heat until melted. This can be done in the microwave or using the double boiling method over a stove. Let sit for ten minutes. 

After those ten minutes the Polysorbate 80 and fragrance oil can be added to the coconut oil and butter mixture. Stir carefully for several minutes until incorporated. 

Carefully, pour the liquid into the dry mixture. 

Put on gloves and gently knead the liquid into the dry mixture until it reaches a wet sand/cookie dough-like consistency. Carefully rub out any white spots within the mixture between your thumb and forefinger until there are no dry spots or clumps. 

Once fully combined the mixture can be placed in a clean silicone mold. If desired, you could also use an ice cream scoop to make bath truffles on a tray lined with parchment paper or foil. 

Pour the mixture gently into the soap mold and use a spatula to smooth out the top. Place the mold into the fridge and allow your mixture to harden for at least one hour. 

It can then be removed from the refrigerator, sliced, and the slices must then be allowed to set for at least 24 hours.

Use

Do not fill bath tub all the way to maximum. Allow at least two inches for bubbles to form. 

Break up one bubble bar into smaller pieces within bath water. Allow time to foam and lather. 

Use non-staining pigment in recipe to avoid staining your tub. We used our mica powders and had no issue with leftover residue.