Black bath bombs are everywhere right now! Made with typical bath bomb ingredients (baking soda and citric acid), they also contain lots of black colorant. Once placed in the tub, the bath bomb turns the water black. The original black bath bomb video quickly went viral. It’s easy to see why. The smoky color that emits from the black bath bomb is hypnotizing.
After receiving lots of questions on how to make black bath bombs, I decided to give them a try. I made two different bath bombs, one colored with activated charcoal and another colored with Liquid Black Iron Oxide. I chose the Liquid Black Iron Oxide because it’s black oxide dispersed in glycerin, which is similar to a La Bomb colorant. To learn more about La Bomb colorants, click here. Since powdered colorants tend to cling to the side of the tub, I was skeptical about the black bath bomb trend. The idea is awesome, but won’t it make a huge mess? Won’t the color stick to the tub and your skin?
For this experiment, I made two different black bath bombs. One made with activated charcoal and another with Liquid Black Iron Oxide.
First, I made one big batch of bath bombs by mixing together 2 cups baking soda and 1 cup citric acid. Then, I split it in half. To one container, I added 4 tsp. of activated charcoal. To the other, I added 40 drops of Liquid Black Iron Oxide. I used my hands to thoroughly mix in the colorants. I added Espresso Fragrance Oil for scent. Once mixed, I spritzed the fizzy mixture with witch hazel until it was the texture of wet sand. Then, I pressed the mixture into Disk Mold & Package.
In the photo below, the activated charcoal bath bomb is on the left, and the Liquid Black Iron Oxide bath bomb is on the right. Because these colorants are not typically used to color bath bombs, they have a “speckly” look to them. The activated charcoal resulted in a slightly darker bath bomb. Once unmolded, I tested the bath bombs in a large bowl of water to get an idea of how they would behave in the tub. See the photos below!
Left to right: bath bomb made with activated charcoal, bath bomb made with Liquid Black Iron Oxide.