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 . We recommend this craft for .

For more hands-on crafts, see how to make slime, salt dough, paper mache, playdough, bubble mixture, oobleck and moon sand with affordable ingredients and easy steps.

Keep the little ones entertained at home with our summer activities for kids, sensory play ideas, fun yoga for kids and birthday ideas for kids at home.

See our new Kid's Kitchen series for essential cookery skills, plus easy recipes kids can make and kids summer baking projects.

4 half-balls
30 mins, plus 2-4 hrs setting

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!

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:

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.

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.

• To , 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.

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Have you tried making your own bath bombs? Leave a comment below…