UXB Bath Bomb Making Tutorial

UXB Bath Bomb Making Tutorial

The UXB ethos is to make products that soothe the skin as you bathe. We wanted to design a bath bomb that foamed and filled the room with delicious scents. A bath bomb that softened the skin without leaving the bathtub a slippery mess. Thus, was born, the moisture bomb. 

Below is a guide to how we make our Sweet Orange moisture bombs. We make it in 3kg batches (approx 17 moisture bombs). If you don’t want to make this many, divide the amounts as appropriate. 

We’ll tell you what each ingredient does as we go along. Some of the ingredients are optional.

Equipment needed


Dry Ingredients Quantity
Sodium Bicarbonate 1600g
Citric Acid 820g
Sodium Lauryl Sulfoacetate (optional) 100g
Kaolin Clay 30g
Cream of Tartar 30g

Wet Ingredients Quantity
Sweet Orange Essential Oil 30g
Lemon Essential Oil 30g
Polysorbate 80 30g
Castor Oil 90g
Witch Hazel Water As needed

Butter Hearts Quantity
Cocoa Butter 60%
Shea Butter 35%
Polysorbate 80 5%


sieve ingredientsThe first job is to weigh and sift the dry ingredients. Both bicarbonate of soda and citric acid have a habit of clumping. Be sure to push it through a sieve to break up any lumps to help mixing later.

If you are adding Sodium Lauryl Sulfoacetate wear a mask. It is a very fine powder and will get into the air very quickly.

mix bath bomb dry ingredientsMix the dry ingredients for 5 minutes or until you are certain they are combined. We use a mixer, but you can do this by hand.

Now we move to the wet ingredients. These will hold the bath bomb together and provide moisturisation.

Mix the wet ingredients together then pour the wet ingredients gently into the dry mix while stirring the dry mix. Keep the mixture moving as you pour.

check bath bomb wet enoughOnce the mixture looks thoroughly mixed check that it is wet enough. To do this grab a handful of the mixture and let go. If you see an imprint of you hand, it is good to go. If it falls apart and looks powdery, you need to add more moisture.

I usually give the mixture a spray of witch hazel water to make sure the moisture bombs bond together.

Forming the Moisture Bomb

piled bomb with heartPile the mixture into one half of the mould. 

If you want to add a butter heart, add it here. Create another mound in the other half of the mould. 

Press the halves together. Make sure that the two spherical sides align to form a perfect sphere. 

Remove the top half of the mould. 

bomb tidyClean up the outside of the moisture bomb so that it looks neat around the circumference. 

Leave the bomb in the bottom half of the mould for at least 24 hours. 

After 24 hours of the bomb falls out of the mould, you’re good to go. If it doesn’t leave it longer or move it somewhere drier.