About a year ago, black bath bombs took the bath and beauty world by storm. This black bath bomb video went viral, and everybody wanted to create their own. Last July, we shared our black bath bomb experiments using various colorants; see them here. Some of the experiments were quite messy.
The takeaway from our experiments? If using charcoal to create black bath bombs, Polysorbate 80 is key! The emulsifier helps mix the charcoal into the water, resulting in less charcoal on your skin and tub.
These Black Salt Bath Bombs get their color from fine and coarse black sea salt. The salt is enriched with charcoal to give it a black color. The fine salt is added to the main bath bomb mixture, while the coarse salt is sprinkled into the molds for a finishing touch.
A good amount of polysorbate 80 disperses the charcoal in the bath water. We found the charcoal mixed into the water rather than pooling on top. Sultry Black Jasmine Fragrance Oil gives the bath bombs an alluring floral scent, perfect for the dark color of the water.
What You’ll Need:
8-10 Disk Mold & Packages
2 cups Baking Soda (Sodium Bicarbonate)
1 cup Citric Acid
1 cup Black Sea Salt – Fine
2-3 oz. Black Sea Salt – Coarse
1 oz. Sweet Almond Oil
0.5 oz. Sultry Black Jasmine Fragrance Oil
0.6 oz. Polysorbate 80
Witch Hazel in a Spray Bottle
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ONE: In a large bowl, mix together 2 cups baking soda, 1 cup citric acid, and 1 cup fine black sea salt. To get rid of clumps in the mixture, you can push the powder through a sifter or break them up with your fingers. Citric acid has a tendency to take off nail polish, so wear gloves to protect your manicure. Thoroughly stir the ingredients together.
TWO: In a separate fragrance oil-safe container, mix together 1 ounce of sweet almond oil, 0.6 ounces of polysorbate 80, and 0.5 ounces of Sultry Black Jasmine Fragrance Oil. Stir to combine.
THREE: Add the oil mixture to the salt mixture and use your hands to thoroughly combine.
FOUR: Test the consistency of the bath bomb mixture. The perfect consistency for molding is a texture similar to damp sand that holds its shape when squeezed. If it’s too dry, use one hand to spritz the mixture with witch hazel and one to mix. Continue spritzing until the mixture holds its shape when squeezed. Below, you can see that the mixture forms a ball when squeezed. This means that the mixture will hold its shape in the mold as well.
FIVE: Sprinkle a small amount of the coarse black sea salt into the bottom of the Disk Mold & Packages. Then, press the bath bomb mixture into the molds. Press the mixture firmly to create a solid shape. Only fill the molds up to the bottom lip, or the lids will not fit.
SIX: Continue filling up each mold with bath bomb mixture. Allow the bath bombs to dry for several hours or up to overnight. Remove from the molds. Place the bath bomb into hot bath water and enjoy!
- About 8-10 Disk & Mold Packages
- 2 cups Baking Soda (Sodium Bicarbonate)
- 1 cup Citric Acid
- 1 cup Black Sea Salt – Fine
- 2-3 oz. Black Sea Salt – Coarse
- 1 oz. Sweet Almond Oil
- 0.5 oz. Sultry Black Jasmine Fragrance Oil
- 0.6 oz. Polysorbate 80
- Witch Hazel in a Spray Bottle
- In a large bowl, mix together 2 cups baking soda, 1 cup citric acid, and 1 cup fine black sea salt. To get rid of clumps in the mixture, you can push the powder through a sifter or break them up with your fingers. Citric acid has a tendency to take off nail polish, so wear gloves to protect your manicure. Thoroughly stir the ingredients together.
- In a separate fragrance oil-safe container, mix together 1 ounce of sweet almond oil, 0.6 ounces of polysorbate 80, and 0.5 ounces of Sultry Black Jasmine Fragrance Oil. Stir to combine.
- Add the oil mixture to the salt mixture and use your hands to thoroughly combine.
- Test the consistency of the bath bomb mixture. The perfect consistency for molding is a texture similar to damp sand that holds its shape when squeezed. If it’s too dry, use one hand to spritz the mixture with witch hazel and one to mix. Continue spritzing until the mixture holds its shape when squeezed. Below, you can see that the mixture forms a ball when squeezed. This means that the mixture will hold its shape in the mold as well.
- Sprinkle a small amount of the coarse black sea salt into the bottom of the Disk Mold & Packages. Then, press the bath bomb mixture into the molds. Press the mixture firmly to create a solid shape. Only fill the molds up to the bottom lip, or the lids will not fit.
- Continue filling up each mold with bath bomb mixture. Allow the bath bombs to dry for several hours or up to overnight. Remove from the molds. Place the bath bomb into hot bath water and enjoy!
I’ve noticed some of the older bath bomb recipes don’t include the polysorbate 80. Was this a newer discovery that formed bath bombs better? Also, can any essential oil be used, for instance, argan oil?
Polysorbate 80 helps create disperse the oils in the water because it is an emulsifier. We didn’t include micas in bath bombs a few years ago, but once we started making more fun kinds, we needed the Polysorbate 80.
You can use any essential oil you’d like. Argan Oil isn’t an essential oil, so we don’t recommend replacing the fragrance with that.
I’ve tried this and one other bath bomb recipe, and the mixture expands out of the mold. I know that means there is water somewhere making the reaction start. I live in a very humid area, does baking soda absorb moisture? or one of the other ingredients, witch hazel ? will the alcohol evaporate and the water be left behind? I tried leaving the baking soda in a warm oven to try to get any humidity out of it, but it still expanded out of the mold. Thanks.
If the bath bombs are expanding, it’s due to moisture – that can be from the humidity in the air or even a lot of witch hazel.
Once you have all your ingredients mixed together, test the powders in your hand. You want it to feel like wet sand and hold its shape when squeezed. If so, you’re ready to mold. If not, mix the powders and spritz with witch hazel until it holds its shape. You can see that consistency here: https://www.youtube.com/watch?v=8bjpsQXt6NU
It also helps to store the bath bombs in a cool, dry place at room temperature. If you have a fan or dehumidifier, you can use that as they harden. Then, wrap them tightly in plastic wrap.
So I’ve been making this recipe for a while now without any issues. The only thing that I changed was instead of buying the Black Sea salt, I just purchased sea salt and added the charcoal myself. Since doing that, 20 bath bombs have cracked, grown warts and exploded. Does anyone have an idea as to why this is happening?? I’m an experienced Bath Bomb crafter and even split the oils in half thinking it would help but it didn’t. I’ve also been using a brand new bottle of black jasmine FO, maybe this has something to do with it?
I’m not sure why that’s happening. Is it cold and dry where you are, or more hot and humid? Bath bomb recipes will react differently based on weather.
It is cold and dry where I live. I’m just gonna assume that my charcoal to salt ratio is much different than Brambleberry’s (1TBS of charcoal for 11oz of salt). Maybe Brambleberry even uses a different process when making the Black Sea salt. My guess is that the charcoal is absorbing the sweet almond oil and making them explode. I went ahead and re ordered the pre made black salt from brambleberry. Let’s hope this helps! If not then it has to be the fragrance oil.
I think the charcoal may be it as well – it absorbs moisture so it is likely making the bath bombs dry. You can try reducing the charcoal or adding more sweet almond to make the mixture more wet.
Is there a substitute for the polysorbate 80? Or can it be left out? We only make all natural products and this looks AWESOME… except for that… thanks!
We recommend polysorbate 80 in this recipe. It’s an emulsifier that helps prevent too much color transfer, and we haven’t found a good substitute for it. Without the polysorbate 80, it can get really messy: https://www.soapqueen.com/bath-and-body-tutorials/black-bath-bombs/
-Kelsey with Bramble Berry
Funny running into this recipe today as I made my first ever bath bombs with charcoal and clay. When I first used them, I was surprised how nicely it mixed in and how even the distribution was. It did not stick to skin or tub, rinsed off quite nicely.
Try it without. 😁
Hi, can i replace the Witch Hazel with something else? In Venezuela is not achieved
The oil in this recipe does help moisturize the bath bombs. If it’s still too dry, you can add more oil until it holds together. You can also try a bit of 99% isopropyl alcohol to wet the mixture.
Get more bath bomb tips here: https://www.soapqueen.com/bath-and-body-tutorials/bath-bomb-questions-answers/
-Kelsey with Bramble Berry
Does this color the tub at all, like the others did even with the Polysorbate 80?
There may be a little bit of transfer, but it’s easy to wipe away with a towel. It also helps to wipe away any residue on the tub before a bath – that’s what the color likes to stick to.
-Kelsey with Bramble Berry
can the black salt be substituted with activated charcoal ?
You can use charcoal instead, but I would recommend using quite a bit less. Too much charcoal will color the tub, even with polysorbate 80. You can see that here: https://www.soapqueen.com/bath-and-body-tutorials/black-bath-bombs/
I would recommend starting with just 1/8 teaspoon, then adding more from there if you like.
-Kelsey with Bramble Berry
Activated charcoal: https://www.brambleberry.com/Activated-Charcoal-P4956.aspx
my melt & pour embeds are melting inside my cold process soap. I realize the humidity is high but the soap is stable just not the melt and pour part
Did you use regular melt and pour, or LCP melt and pour?
-Kelsey with Bramble Berry
Does this color the water at all?
It colors it anywhere from a very light to dark gray, depending on how full your tub is.
-Kelsey with Bramble Berry
Can you make a video of the black sea salt bomb in water?
I’d also love to see this in action! looks like a cool recipe.
Thanks for the suggestion!
-Kelsey with Bramble Berry
Hello – for a long time I have been a happy follower of the Soap Queen blog, and looked forward to it appearing in my email box. Lately, however, I have been wondering why there is nothing but bath bomb recipes, to the exclusion of everything else. Certainly bath bomb are enjoyable and fun to make, but there are so many other recipes that people enjoy – soaps, lotions, lip products, etc. Why have they all been ignored for a steady stream of bath bomb recipes? I would really like to see some of them being covered. Thank you, Nancy Smyth
We have some really fun recipes coming up I think you’ll like, including cold process soap, melt and pour soap, scrubs, body butters, etc. Look out for those soon. 🙂
-Kelsey with Bramble Berry