Method Make sure all your equipment is totally dry as any moisture will start the ingredients fizzing.
Sieve the baking soda and the citric acid together into a bowl and mix well.
Sieve the dry ingredients
Add the oils and the food colouring together in a second bowl.
Wet ingredients in a separate bowl
Pour the oils into the bowl with the baking soda/ citric acid mix. Mix with your fingers very quickly. If you dont mix quickly the fizzing reaction may set off.
Mix quickly with your fingers
The mixture should be powdery but start to clump together if you squeeze it. Add a tiny bit more oil if needed.
The mixture should by powdery but clump when squeezed
Press the mixture into the ice cube molds. It's important that it is very hard packed to stop the finished bath bomb crumbling apart, so put in a spoonful at a time pressing it in very firmly with your fingers before adding another spoonful.
Ready to be pressed down firmly
We made hearts, stars and fish using these cheap ice cube trays from IKEA
Leave to dry for at least 24 hours
Remove the bath bombs carefully from the molds
Fun fizzy fish
Add one to your bath and enjoy the fizz!
In humid or damp conditions, the finished bath bombs will quickly pick up moisture from the air and start to develop a bubbly surface. It's best to keep them in a dry airtight container and plan to use them within a few days.