Ages 9+

Planet Bath Bombs


Learn about chemistry and design out-of-this-world bath bombs! Mix together citric acid, baking soda, cornstarch, and food coloring to make your bath bomb base before pressing into molds. Smush and sprinkle the colors on top of each other to create planetary layers before dropping them in the bath and watching them fizz!

Why it’s awesome

  1. Just add water

    Everything you need to make four multicolored bath bombs.

  2. Planetary fun

    Create bath bombs inspired by real-life and make-believe planets.

  3. Fizzy chemistry

    Experiment with scents, colors, and more to make custom bath bombs.

What’s included?

  • baking soda 5 oz (144g)

  • citric acid 2.5 oz (73g)

  • cornstarch 2.5 oz (73g)

  • Epsom salt 2.5 oz (73g)

  • olive oil 0.6 fl oz (18 ml)

  • 3 food coloring bottles, each 0.17 fl oz (5ml)

  • spray bottle

  • 3 paper bowls

  • 6 molds

  • mess mat

  • tube

  • gloves

  • illustrated instruction booklet

Topics explored

  1. Chemical reactions

  2. Mixing colors

  3. Planetary layers

From the desk of the product designer:

Behind the design

We wanted to make the bath bomb experience more educational. Now kids can learn about the anatomy of a planet while making their bath bombs, from core to crust!

- KiwiCo Product Designer

By the numbers


Planets created during testing


Planets cut open


Test baths



19 reviews

Customer images



    I did this project with my 9 year old and he loved every step! We were worried that the consistency wasn't right but once the bath bombs dried, they held together perfectly.



    I liked making them, but I thought the color would stay longer and that it would be more sudsy when I bathed with it.



    My son loved making these and then using them at bath time. He had fun doing the store by step process and doing different color combos. He could not believe how fizzy they were when he got to used the finished product. He made a total of 5 bath bombs. This was such a good gift.



    Perfect gift for my Granddaughter



    We love this box! the kids had so much fun with it!



    I would love it if you included the measurements for the ingredients so that we could make them again using the equipment that was provided.

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