Make your own free website on

Cool Science Club

Fizzy Bath Bombs

Home | Resources | Cool Science Club Projects | Cool Science Web Sites! | Science Club Photo Album | Start a Science Club

How To Make a Fizzy Bath Bomb


Better Bathing through chemistry!  Combine household ingredients to make a fizzy, fun, scented treat for the bath.   


  • 1 Spoonful citric acid  powder (obtained from drugstore)
  • 1 Spoonful cornstarch
  • 2 Spoonfuls baking soda
  • 3-4 drops fragrance oil
  • 3-6 drops food color
  • 2 Spoonfuls vegetable oil
  • Mixing cup
  • Waxed Paper
  • Optional: a pinch of  lavender or oatmeal


  1. Mix all dry ingredients (citric acid, cornstarch, baking soda) in a cup.
  2. Add the vegetable oil, fragrance, and coloring. Mix well to form a thick, dry paste, a little drier than toothpaste.  Add a few pinches of cornstarch if too runny, or a few drops of oil if too dry. 
  3. Place 3/4" balls of the mixture on waxed paper. They will be semi-hard within 2-3 hours, but allow 24-48 for them to fully dry before storing them.
  4. Store bath balls in a sealed container, away from moisture.
  5. Add a few to the bath and enjoy! For gift giving, the balls may be placed in individual candy cups.


  1. Either fragrance and/or coloring is optional.  
  2. Suggested vegetable oils include coconut oil, avocado oil, apricot kernel oil, sweet almond oil, or olive oil, although any emollient oil is good!  Cooking or salad oil from the grocery store works fine.
  3. Use small molds to make three-dimensional fizzy bath shapes.
Thanks to for this project.

The Science:
The citric acid reacts with base sodium bicarbonate (baking soda) when exposed to water to create bubbles of (mostly)carbon dioxide gas and a resulting salt which is pleasant for bathers.



Check out all the Cool Science projects at