How to make a bath bomb
Try making your own homemade bath bombs for an easy kitchen project that kids will love – give these as gifts or use them to make bath times more fun.
Making bath bombs is a great indoor activity that will keep the kids busy on a rainy afternoon – and they're also a lovely gift for friends and family.
Experiment with colours, add flowers from your garden and use different shapes. Once you have the main ingredients, it's really easy to adapt this recipe to what you already have at home.
These ingredients are safe to use in the bath, but it's important to note that bath bombs are inedible. We recommend this craft for children aged eight years or over.
Browse our family & kids hub for plenty of inspiration.
How to make a bath bomb
Bath bomb recipe
Makes 4 half-balls
Prep 30 mins, plus 2-4 hrs setting
- 100g bicarbonate of soda
- 50g citric acid
- 25g cornflour
- 25g Epsom salt (optional)
- 2 tbsp oil – such as sunflower, coconut or olive oil
- ¼ tsp essential oil, such as orange, lavender or chamomile
- a few drops of liquid food colouring
- orange peel, lavender or rose petals, to decorate (optional)
You will also need
- mixing bowl
- plastic moulds (see below for ideas)
1. Put the bicarbonate of soda, citric acid, cornflour and Epsom salt in a bowl, then whisk until fully combined.
2. Pour the base oil, essential oil and food colouring in a small bowl. Mix together well, combining the oil with the colouring as much as possible.
3. Very slowly add the oil mixture into the dry ingredients a little at a time, whisking between each addition. When all the oil is added, add a few tiny drops of water and whisk again (it will fizz when you add the water, so mix it in quickly). You're looking for the mixture to slightly clump together when pressed in your hand and keep its shape – it shouldn't be too wet.
4. If you're adding peel or flower petals to decorate, drop them into the bottom of your chosen mould. Pack your mixture tightly on top, pressing down and smoothing out the top with a teaspoon.
5. Leave your bath bomb in the mould to dry for 2-4 hrs, then carefully remove it. It's now ready to drop into the bath – watch it fizz away!
What can I use as a bath bomb mould?
You can use anything flexible as a mould for your bath bombs, so have fun looking around your home for things you could use. Here are some ideas to get you started:
- Yogurt or pudding pots
- Christmas tree decorations (we used a star)
- Plastic packaging from toys
- Easter egg packaging
- Silicone ice cube trays
- Silicone cupcake cases
- Plastic biscuit cutters (place them on a tray)
For children, we suggest making half-shapes as it can be tricky to make a sphere that sticks together. If you want to make a complete sphere, you'll need a two-sided mould. Slightly overfill each side with the mixture, then press firmly together and secure with elastic bands while it dries. Be very gentle when you remove them from the moulds.
Where can I buy citric acid?
Citric acid is often used in homemade cordials and winemaking – you'll find it as an ingredient in shop-bought bath bombs. The reaction with the bicarbonate of soda is what makes your bath bomb fizzy.
You can buy citric acid online and from some larger pharmacies. For our recipe, we used Wilko citric acid.
Top tips for making bath bombs
- Be sure to use liquid food colouring, not gels. Gels will clump together when you add them to the bicarbonate and it's hard to mix them in.
- Once you've added the liquid to the mixture, you need to work quickly to mix everything together and push it into the mould as soon as you can.
- To allow your bath bombs to dry, leave them uncovered in a cool, dry place (away from taps and humidity). They will take longer to set in humid weather.
- If you've got more than one colour, why not make a rainbow bath bomb? Layer up the different colours and they will blend together beautifully.
Looking for more kids' activities?
Have you tried making your own bath bombs? Leave a comment below…