These cute looking pink petal bath bombs have a dark secret hidden inside. Learn how you can make these hidden black bath bombs at home.
You can keep them all to yourself, or share them as gifts with family and friends. How about a Halloween sugar-free alternative for Halloween? Or the perfect anti-Valentine or Galentine present? Even underneath the Christmas tree I know you can think of someone who’ll fall in love with these bath fizzies.
I’m actually a little late to the black bath bomb party that has been happening all over Pinterest, Instagram and You Tube.
Because it’s been done before, I never felt like I could add anything new by turning it into yet another DIY.
But then this thought popped up in my head: what if you can’t SEE it’s a black bath bomb? What if it’s a black bath bomb in disguise? What if I took the black bath bomb to a whole new level of creepy?
First it starts as a pretty rose petalled bath bomb. But as it fizzes the black starts to ooze out from the sides, leaving a trail of darkness behind.
Because of the difference in proportions between the mini bombs and big bombs they also start to move around in your bath water. Like they are haunted or something.
Watch it spin!
Creeped out already? I know you’re intrigued to find out more!
If you like this DIY then don’t forget to put a pin on it! 😉
How To Make Black Bath Bombs
The idea behind these hidden surprise bath bombs is to make a smaller black bath bomb that fits into a larger bath bomb.
To make the black color of the smaller bath bombs as vibrant as possible I used 2 ingredients: liquid colorant and activated charcoal.
The obvious choice is of course to use a black colorant. But that’s a color that’s usually not that easy to find. I actually didn’t have black coloring in my stash either.
But when I was trying to make purple for my DIY Unicorn poop bath bombs I found out that if you combine red and blue it actually turns a murky black. So for this DIY I diluted a few drops of red and blue coloring in a teaspoon of almond oil.
You can mix different colors together until you get the color you want. Next time I’m going to experiment by adding green and orange coloring to the mix.
As you slow add the oil to the dry ingredient, the mixture will turn a very, very dark emerald green/black.
For extra drama you can add activated charcoal. I added 12 capsules in total. This really intensified the blackness of the bath bombs. Adding activated charcoal also makes the color show more in your bath water.
Now I hear you wondering:
Do Black Bath Bombs Stain the Bath Tub?
It depends on the ingredients you use. Activated charcoal can definitely leave a black spotty residue in your bath tub. If you don’t like the sound of this, you can easily leave it out. Just use all black liquid coloring instead.

Hidden Black Bath Bombs Recipe
This sweet looking floral bath bomb has a dark surprise hidden inside! Learn how you can make your own mini black bath bombs and hide them inside these pretty bath fizzies. They make a great gift idea for Halloween, or for that special someone that secretly has a dark side.
Materials
For the Black Mini Bombs
- 1/4 cup citric acid
- 1/4 cup baking soda
- 2 tablespoons corn starch
- black (or red, green and blue) soap or food coloring
- 1 teaspoon carrier oil (like almond oil)
- 12 activated charcoal capsules (optional)
- essential oil of your choice
For the Big Bath Bombs
- 1/4 cup baking soda
- 1/8 cup citric acid
- 1/8 cup corn starch
- spraying bottle with witch hazel or water
- Dried rose or flower petals (optional)
Tools
- Smaller and Larger Bath Bomb Molds
- Mixing bowls and spoons
Instructions
First, Make the Black Bath Bombs
- Combine citric acid, baking soda and corn starch in a bowl.
- Dilute a few drops of the liquid colorant in 1 teaspoon of oil. I used almond oil. You can also add a few drops (10 to 30 drops) of essential oil in your favorite scent to the carrier oil.
- Slowly add the oil to the mixture. Stir well until combined.
- For extra drama you can add activated charcoal. I added 12 capsules in total.
- Put about 1 tablespoon of witch hazel or water in a spraying bottle. Spray the mixture and stir well each time. Do this until the mixture starts to clump together.
- To make sure the bath bomb will float, scoop some mixture into both sides of the mold. Make sure both sides are overflowing. Next, press both sides firmly together to form a bath bomb. Set aside to cool.
- Give the mini bath bombs time to set and dry. I actually left them to cure overnight just to be sure.
Next, make the Big Bath Bomb
- Combine the citric acid, baking soda and corn starch in a bowl.
- Put about 1 tablespoon of witch hazel or water in a spraying bottle. Spray the mixture and stir well between each spray. Do this until the mixture starts to clump together.
- Take your biggest bath bomb molds. Put about a teaspoon of crushed rose petals or other flower petals at the bottom of one (or both sides) of each mold.
- Start filling each half with the mixture pushing it to the sides. This way you create a hole for the black mini bomb. Kind of like an egg in a bird's nest.
- Put the mini bomb in the middle on one side. Scoop some more mixture in both sides of the mold until they are overflowing. Press both sides together. The mini bomb should be completely surrounded by the big bath fizzy.
- Let the bath bombs dry and set overnight.
These make the Ultimate surprise gift for your Valentine or a perfect Anti Valentine treat for yourself!
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Melissa Wise
Saturday 25th of May 2019
Hi! Not sure if I read through this too quickly and overlooked it, but how many mini bombs can I make from your instructions and sizes of each product available in the links you provided? I'm looking to do this with 30 - 35 kids!
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Friday 27th of April 2018
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deborah smooth
Tuesday 26th of December 2017
nice blog post! the hiding black bath bomb is a good thing. Thank you for sharing such an important knowledge
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Saturday 8th of July 2017
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Lori
Thursday 25th of May 2017
Hi – love this tutorial! I make soap and bath bombs, but I’ve had a couple of folks say that the bombs stain their tub and skin. I use the same coloring for both products. Have you had any trouble with staining? And would you mind sharing what kind of soap coloring you use?
Thanks so much!!
Alison
Thursday 21st of February 2019
Try polysorbate 80. Will help with dispersion and staining
The Makeup Dummy
Monday 7th of August 2017
Hi Lori, I've used both soap and food coloring from different brands and I've never experienced any staining! Maybe you used too much oils or butters? The only thing I can think of is that the colored oil sticks to the edges and makes it seem like it's the colorant staining the bath tub. I hope this helps!