Mondo Oatmeal Bath Bomb DIY
Recipe type: Bath Bombs
Serves: About 7 Bath Bombs
These Mondo Oatmeal Bath Bombs feel soothing and luxurious in the tub.
  • Stainless Steel Bath Bomb Mold
  • 4 cups Baking Soda (Sodium Bicarbonate)
  • 2 cups Citric Acid
  • 1 oz. Colloidal Oatmeal
  • 4 oz. Cocoa Butter
  • 1 oz. Oat Extract
  • 0.7 oz. Oatmeal Milk and Honey Fragrance Oil
  • 0.6 oz. Polysorbate 80
  • Witch Hazel in a Spray Bottle
  • Optional: Cyclomethicone
OPTIONAL MOLD PREP: Cylomethicone helps the bath bomb release more easily. Pour a small amount on a cotton ball and coat both halves of the mold. This step is optional, but if you have never used the Stainless Steel Bath Bomb Mold before, it’s recommended.
  1. In a large bowl, mix together the baking soda, citric acid, and colloidal oatmeal. To get rid of clumps in the mixture, you can push the powders 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.
  2. Add the cocoa butter to a small heat and fragrance-safe container and melt in the microwave using 30-60 second bursts. Be careful when removing from the microwave as the container may be hot. Add 0.7 ounces of Oatmeal Milk and Honey Fragrance Oil, 0.6 ounces of polysorbate 80, and 1 ounce of oat extract to the melted butter. Use a spoon to fully mix the ingredients together.
  3. Add the oil mixture to the powder mixture. Use your hands to fully mix the ingredients together.
  4. 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.
  5. Add a pinch of oatmeal to the bottom of one half of the mold and cover it with bath bomb mixture. Press the mixture lightly into the mold. Fill the other half of the mold and press the mixture in lightly. Then, scoop more of the mixture on top until it’s mounded in the center. Fill up the second half of the bath bomb, mounding the mixture in the center again. Having loose bath bomb mixture on both sides of the mold and a mound in the center acts as the “glue” when they are pressed together.
  6. Press the two halves of the mold together firmly until they touch. Then, begin to twist and pull the top half off carefully. Once the top half is removed, allow the bath bomb to sit in the bottom half for several hours up to overnight. If they don’t stick together the first time, keep trying. It can be a little tricky to get the bath bombs to stick together, but practice makes perfect! See how to use the stainless steel molds in the How to Make Bath Fizzies video on Soap Queen TV.
  7. Repeat the process with the other bath bombs. When they’re unmolded, allow them to sit for 24 hours before using or wrapping in plastic wrap to protect them from excess moisture. Learn more about packing and storing your bath bombs in the How to Store Handmade Bath Products post.
Recipe by Soap Queen at