Make your own Bath bomb

Bring chemistry into the bathroom. Make bath time fun!

Make your own bath bomb from household ingredients and marvel over the fizzy, colourful chemistry happening around you.

Suitable for kids aged 6+
You Need:
  • Food colouring
  • Sweet Almond oil (use different oil if allergic to nuts)
  • 10 tablespoons of bicarbonate soda
  • 3 tablespoons of citric acid
  • 2 large mixing bowls
  • 1 large muffin tray
  • 1 small glass jar
  • Rubber gloves
  • Spoons
  • Scented oil, glitter or flower petals
  • Spoons
What to do:
  1. Grease the sides and bases of a large muffin tray with a small amount of almond oil. (Use an alternative oil if allergic to nuts.)
  2. Place the citric acid and bicarbonate of soda into a large bowl. Mix the ingredients together well.
  3. Add flower petals or body glitter to base mixture if you please.
  4. In the small glass jar, mix together 6 drops of scented oil, 5 teaspoons of sweet almond oil and about 10 drops of food colouring.
  5. Gradually pour this oil mixture into the base mixture. While wearing rubber gloves, quickly mix it all together. The mixture is ready when it stays together in your hands without crumbling too much.
  6. Spoon the mixture into the muffin tray. Press it down firmly.
  7. Leave the bombs in the tray to set for a few days.
  8. Carefully up-end your bath bombs to remove them from the moulds. Then run a bath, drop a bomb and watch it fizzzzzz!

Why is it so?

Bath bombs create colourful patterns and fizzy sounds due to an acid-base chemical reaction. Once the bath bomb is dropped in the water there is a chemical reaction between citric acid (acid) and the sodium bicarbonate (base). The fizzing you can hear and the bubbles you can see are due to a gas called carbon dioxide, which is being released during this reaction.

Sweet almond oil is also released in this chemical reaction, forming a thin layer on your skin which will help moisturise it. Experiment using different scents and colours!