Bath bomb color help

Soapmaking Forum

Help Support Soapmaking Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.


New Member
Apr 21, 2016
Reaction score

I currently make bath bombs using mica to color them and they turn out rock hard and perfect pretty much every time. I have been experimenting using different coloring agents to try to get a richer color in the bath without leaving residue on the tub.
I use the same recipe but instead of the mica I have subsituted with a few drops of liquid color (ingredients: glycerin and red 30) for example. Every time I use the liquid color by bath bombs seem hard for the first day or two but about 3-5 days in they stay turning soft and expanding.
Here is the basic recipe Im using :

Baking soda 1cup
Citric acid 1/2 cup
Epsom salt 1/4 cup
Coconut oil 1 tbsp
Fregrance 3-9ml
Color 1 scoop of mica or 3-6 drops of liquid.
A few Spritz of witch hazel

i am open to any and all suggestions at this point. I have used bramble Betty's la bomb colors, rustic essentials gel colors and a gel toner from a local lady all with the same results.
Glycerin is probably drawing moisture out of the air. Are you in a very humid area or has it been raining lately where you are? Once they get their initial hardening, maybe try wrapping them?
I'm in Sacramento. It has been rainy but does that mean I'm out of luck? I have tried wrapping them and they still end up getting soft inside the shrink wrap after a few days and expanding as much as they can And if they seem fine I try to unwrap them and they just crumble. Is there a different type of color I could use that would color the water without leaving a residue?
I agree that it's the glycerin causing your issues. I use either mica or the bath bomb colorant from WSP or Nature's Garden. I don't make a whole lot of them but it has worked for me. I also don't make them really bright or super saturated in color.
I started adding a bit of polysorbate 80 in mine and they quit leaving a colored ring in my tub. Granted, I don't use an extremely heavy color to begin with but even what I did would leave a ring. The PS80 helps to emulsify the oils I add with the water. The oils were what was causing my ring.

Latest posts