What Bath Bomb Recipes Can You Make with Cream of Tartar and Citric Acid?

Citric acid drives the fizz, reacting with baking soda the moment it hits water. Cream of tartar is a weaker acid that hardens the bomb, makes it easier to mold, and extends the fizzing action so it lasts longer in the tub rather than exploding all at once. A reliable base recipe is 2 parts baking soda, 1 part citric acid, and cream of tartar at roughly half the amount of your citric acid. For every cup of baking soda, that means half a cup of citric acid and a quarter cup of cream of tartar. From there, add a light oil like fractionated coconut oil at about 2 tablespoons per batch, fragrance oil at your supplier's recommended usage rate, and witch hazel spritzed in slowly until the mixture holds together like damp sand when squeezed.

You can get creative with add-ins. Epsom salt softens the soak and adds weight to the finished bomb. Kaolin clay gives a silkier feel in the water and helps with hardness. Polysorbate 80 keeps any oils from floating on the surface and clinging to skin rather than the tub walls. Colorants and micas can be added dry or pre-mixed into your oil portion for more even distribution. Keep citric acid as your primary acid, regardless of what you add. If you replace too much of it with cream of tartar, you lose the dramatic fizzing effect that makes bath bombs worth making.