What makes the fizz in bath bombs? Baking soda and citric acid combined with water.
Baking soda / sodium bicarbonate can be found in most supermarkets in the baking section. It has anti-inflammatory and acid-neutralising properties when used in bath bombs and can also relieve itchy skin.
Citric acid is a naturally occurring acid found in fruits and vegetables. It is also used as a preservative in food and cosmetics.
What You Will Need:
- Stainless steel bath bomb mould or muffin tray
- Bicarbonate of Soda (sodium bicarbonate)
- Citric Acid
- Epsom Salt
- Essential oil or Fragrant oil
- Liquid Colour for bath bombs or food colouring
- Spray bottle
- Waxed paper
- Baking tray
- Water based colours
- Large mixing bowl
- Small bowl
For this particular recipe, we will be using:
- 2 cups baking soda
- 1 cup citric acid
- 1 tablespoon of vegetable oil /butter (Your choice! Eg. coconut oil, rice bran oil, shea butter)
- Food colouring or specialty bath bomb colouring
- 3 ml of skin safe fragrant oil or essential oil
- A spray bottle with water
- Disposable gloves
- Muffin tray (or a specialty bath bomb mould)
Step 1: Prepare The Area
Cover the table with waxed paper.
Step 2: Sieve And Stir Dry Ingredients
Mix 2 parts of sodium bicarbonate to 1 part citric acid into a large mixing bowl. Therefore you can combine 2 cups of baking soda with 1 cup of citric acid in a bowl and mix with your hands.
Step 3: Colour & Fragrance
- In separate bowls, it's time to prepare your liquids. Measure out your oils. Oils will moisturise and improve the skin. Choose the vegetable oil or butter you have in stock or that appeals to you. Shea butter, coconut oil and sunflower oil all have different benefits, for example.
- Measure your chosen essential or skin safe fragrant oil. Be sure to check the product you are using for maximum use percentage recommendations. In general, 3 ml of essential / fragrant oil can be added to every 1 cup baking soda/1/2 cup citric acid mixture.
Leave your bath bombs white. Or, prepare a few drops of your chosen colour. Ensure that you are using colour designed for bath bombs or food colouring works too. This is where disposable gloves will come in handy. You can always add more colour later to reach the shade that you like.
Step 4: Blend Dry and Wet Ingredients Together & Check Consistency
Blend your dry ingredients with your oils and butters slowly with a spoon or with your hands (with or without gloves is okay). Then add your fragrance and colour.
You can spritz the mixture occasionally with the spray water bottle. Do this very slowly to ensure that you don’t activate your mixture (you don't want it to fizz just yet). You really need to get that ratio of dry mix to wetness correct.
When your mixture is blended, its time for it to be squeezed firmly to test if it’s ready for moulding or not. Ensure that its still a little dry when you move it and not too moist - like wet sand that holds its shape in a sandcastle. If you drop a bit of squeezed mixture into your bowl, check that it doesn't break apart completely. If it does this, add some water or colour. If your mixture is soggy, add more bicarb and citric acid to it.
Step 5: Moulding
Once you're happy with your mixture, spoon the mixture into the bath bomb moulds. Make sure you pack the moulds tightly until both cavities are overfilled. Now gently push the two mould halves together and squeeze them together. If you're using a muffin tin. ensure the bottoms are flat.
Once you've mastered this, in future you can add dried rose petals and glitters.
Step 6: Un-moulding
There is no need to leave the bath bombs to set. It's time to un-mould almost immediately. The longer you leave it in the specialty bath bomb mould, the harder it will be to release.
Twist and pull away one half of the mould. Now flip it over onto the palm of your hand to reverse to the other side, and pull the other half. Repeat with the rest of your moulds.
- If you're using a muffin tray, carefully un-mould them onto a baking tray covered in waxed paper. No need to put the 2 side together. Leave them to dry out over night.
Step 7: Set & Store
Leave the un-moulded bath bombs on the wax paper or a baking tray or in the muffins tin, so they can’t roll away.
Cover the bath bombs with a dry tea towel and air dry for at least 24 hours to fully harden.
Store in an airtight container, in glad wrap or cellophane bags and use as needed.