You will need a large mixing bowl and two smaller bowls, bath bomb moulds, scales and a small water spray bottle containing cold water.
300g Bicarbonate of Soda
100g Citric Acid
A few drops of essential oils
(I used Serenity, Geranium, Lime and Wild Orange )
Powdered Food Colouring
Mix and sieve the Bicarbonate of Soda and the Citric Acid. Add a small amount of food colouring, a little at a time, to get the desired shade. Mix again, to incorporate all of the powder.
Add 6-8 drops of essential oil to each bowl (we used one oil, but you could add a combination of oils) and then spray a little water onto the mix and keep spraying as you combine.
You really do need to mix continuously to avoid it fizzing up, and only add enough water to hold the mixture together when lightly squeezed in your hands. It should just hold together and not be too damp.
Press the mixture hard into the moulds and level the tops. Leave to dry for at least 30-60 minutes. It may take longer to dry, depending on the dampness of the mixture. Remove gently from the moulds.