Learn to make easy DIY bath bombs using a simple recipe and natural ingredients. They will come out perfectly every time - I promise!
My kids absolutely love bath bombs. Seeing them fizzing away in the tub brings them so much joy. Bath bombs simply give your bath time this special sparkle and excitement while at the same time delivering gorgeous scents and skin-loving goodness. If you make your own bath bombs, you can save a lot of money compared to store-bought. Aaand, they make a great gift. What's not to like?
I've experimented with different ingredients and techniques over the years. In this article, I will show you how to make bath bombs using a simple bath bomb recipe without a ton of ingredients. But the secret to creating perfectly round, crumble-free bath bombs is to let them dry in the mold. The molds I'm using are great for that, plus they double as the perfect packaging.
What are bath bombs, and what do they do?
Bath bombs comprise two main ingredients: baking soda and citric acid. Mixing both together will set off a fizzing reaction when immersed in water. Baking soda on its own adds some health benefits to the bath water, but typically, a bath bomb is used to deliver additional skin-loving ingredients (like essential oils, oils, bath salts, milk powder, etc.) to a bath in a fun way.
This post contains affiliate links, you can read my full disclosure here.
Ingredients
- ½ cup citric acid
- 1 cup baking soda
- ¼ cup cornstarch
- 1 tablespoon of grapeseed oil (you can substitute with sweet almond oil, melted coconut oil, canola oil or olive oil instead)
- 15 - 20 drops of lavender essential oil (optional)
- food coloring (optional) - choose any color, I opted for purple and used a couple of big squirts
- ½ tablespoon of polysorbate 80 (optional, will help keep your tub slick-free)
- witch hazel
Equipment
- large bowl
- a spray bottle for the witch hazel
- bath bomb molds - I love using these Christmas tree ornaments, they work so great, and you can use them as packaging
- sifter (optional)
- gloves (optional)
How to Make Bath Bombs at Home
- Combine baking soda, citric acid, and cornstarch. Work out any clumps with your fingers, or use a sifter.
- Add oil, essential oil, Polysorbate 80 (if using) and mix with your hands
- Add food coloring (if using) and mix thoroughly
- Spritz with witch hazel until the mixture reaches a wet sand consistency. Test by squeezing the mixture in your fist and see if it's firm enough to hold its shape and won't crumble if you tap it gently with your finger (pictured above).
- Loosely fill each half of your bath bomb mold. Filling until it's heaped up.
- Remove any excess from the sides and top
- Firmly squeeze both halves together until the mold fully closes
- Set aside and let dry overnight
- Gently take out of the mold and store in an airtight container or wipe the outside of the mold clean and decorate it with lavender twigs and a pretty ribbon
How to Use a Bath Bomb
Fill your tub, drop in 1-2 bath bombs, and watch them fizz. When it's done fizzing, you might want to move the water around a little bit with your hand. Get in the tub, soak and relax after a long day of work.
Caution: Bath bomb recipes that contain oil or butters can leave a slick film on the bottom of your tub. Exit the tub carefully and help your kids get out safely. If you wish to counteract the slipperiness, add polysorbate 80, it will help disperse the oil mixture evenly in the water without sticking to the tub.
Can You Make Bath Bombs without Citric Acid?
Can you make bath bombs without citric acid? The short answer: Yes, but it won't fizz as much! My friends over at CountryHillCottage have a great recipe you can try.
If you're concerned about citric acid being made from genetically modified fruit, I suggest you use non-GMO citric acid that you can find here.
What does Cornstarch do in Bath Bombs?
Cornstarch is used in many homemade bath bomb recipes as "buffer" if you will. Citric acid and baking soda are very reactive and will fizz and create a chemical reaction quickly when exposed to moisture.
By adding cornstarch to the mix the citric acid and baking soda don't sit quite as closely together. Therefore, your bath bomb will fizz longer and more moderate. Also, you can reduce the risk of your bath bomb fizzing up before it hits your bath (when exposed to moisture, etc.).
Can I use Food Coloring to Color my Bath Bombs?
Yes, you can. Gel food coloring will give you a stronger color but is tougher to incorporate. Regular food coloring will work as well, but it might set off the fizzing reaction due to its water content.
Do I have to Use a Special Bath Bomb Mold?
No, one of my favorite "molds" is a stainless steel ¼ cup measuring up. I used it to make these Lime Coconut Milk Bath Bombs. You can also use an ice cube tray or a silicone baking mold.
Tips for Making Bath Bombs
- Avoid making bath bombs when the air is very humid (e.g. it's raining or has rained for the last few days). The mixture will absorb the moisture in the air and never really set up.
- Pay close attention to the consistency of your batter before putting it in the mold. It takes some practice to be able to notice the right consistency. I typically squeeze the mixture and see if it holds its shape. If it does I give it a little tap with my finger so I can gauge the firmness. If not firm enough, I will add a couple more spritzes of witch hazel. A mixture that's too wet will not harden enough and will not hold its shape once unmolded. A mixture that's too dry will crack or crumble upon unmolding.
- Sift your dry ingredients or really try to work out any clumps with your fingers. If there are clumps in your mixture, you run the chance that your bath bombs develop "warts." It looks like the bath bomb has little protruding growths on it.
For Humid Weather
- Omit any type of salts (epsom salt, sea salt, etc.) from your bath bomb recipe. Salts will attract moisture and mess with your final product.
- Keep in mind that your mixture might already have enough moisture from the humidity in the air before adding any witch hazel or isopropyl alcohol. Do your squeeze test and decide if you need to add any more moisture.
- Use a plastic mold or Christmas ornament that interlocks. I've had good results with this type of mold as I find it creates a tight enough seal to keep any moisture out.
- You could look into "baking" bath bombs at 170º F in the oven for a couple of hours, then turn it off and let the bath bombs dry in there overnight.
Troubleshooting
Why did my bath bomb crack? Why did my bath bomb crumble?
Oftentimes, you'll see cracks or crumbly sides after the bath bomb has been set out to dry. Most likely your mixture was too dry when you molded the bath bomb. Try using a little bit more liquid (witch hazel or isopropyl alcohol) or oil next time. Remember only to add a little at a time and check the consistency often. Too much moisture will make your bath bomb too soft.
Why did my bath bomb halves not stick together?
There can be several reasons for separated bath bomb halves:
- Your mixture is too dry, and the halves can't stick together properly
- You didn't fill your mold enough before pressing the halves together. Remember to really mount the mixture as high as you can.
- You twisted the two spheres and thereby separated the halves from each other
- Try the instructions in this recipe and leave the bath bomb drying in the closed mold overnight
Until next time. Happy Tinkering!
Looking for more fun bath bomb recipes? Try:
Homemade Bath Bomb Recipe (printable)
These easy bath bombs will come out perfectly every time, the secret is to let them dry in the mold. You're only a few steps away from a relaxing bath experience!
Ingredients
- ½ cup citric acid
- 1 cup baking soda
- ¼ cup cornstarch
- 1 tablespoon of grapeseed oil (you can substitute with sweet almond oil, melted coconut oil, canola oil or olive oil instead)
- 15 - 20 drops of lavender essential oil (optional)
- food coloring (optional)
- ½ tablespoon of polysorbate 80 (optional, will help keep your tub slick-free)
- witch hazel
Instructions
- Combine baking soda, citric acid, and cornstarch. Work out any clumps with your fingers, or use a sifter.
- Add oil, essential oil, Polysorbate 80 (if using) and mix with your hands
- Add food coloring (if using) and mix thoroughly
- Spritz with witch hazel until the mixture reaches a wet sand consistency. Test by squeezing the mixture in your fist and see if it's firm enough to hold its shape and won't crumble if you tap it gently with your finger (pictured above).
- Loosely fill each half of your bath bomb mold. Filling until it's heaped up.
- Remove any excess from the sides and top
- Firmly squeeze both halves together until the mold fully closes
- Set aside and let dry overnight
- Gently take out of the mold and store in an airtight container or wipe the outside of the mold clean and decorate it with lavender twigs and a pretty ribbon
Notes
Equipment
- large bowl
- a spray bottle for the witch hazel
- bath bomb molds - I love using these Christmas tree ornaments, they work so great, and you can use them as packaging
- sifter (optional)
- gloves (optional)
Aimee says
Hi there
what is the witch hazel for? can I use a witch hazel and rose water mix?
Celine says
Hi Aimee,
great question! Witch hazel is used to achieve the wet sand consistency of the bath bomb mix before you mold it. Depending on your climate you might not even need it, if the recipe contains enough liquid oils, butter and essential oils and you live in a humid climate. I like to use witch hazel or 90% rubbing alcohol since these don't set off the fizzing reaction when added to the mix. You can use rose water sparingly, too much will cause your mixture to fizz. Happy Tinkering 🙂
Ashley says
I have witch hazel mixed with rose water, can I use that? Not just the rose water, but the witch hazel is mixed with the rose water already
Celine says
Yes you can sparingly in a spray bottle while you whisk the mixture. Happy Tinkering!
Loan says
My bomb is not fizzy. I dont know the reason. Could you please tell me more?
Celine says
Hi Loan, two things come to mind. Either your baking soda or citric acid was past its expiration date/ exposed to humidity or your finished bath bomb wasn’t properly stored and was exposed to humidity. Hope that helps. happy Tinkering 😃
marie says
hi, is it possible you could pint me the direction of the mould you used in the video please? it isn't the one linked x
Celine says
Hi Marie, it’s the stainless steal one from Brambleberry https://www.brambleberry.com/shop-by-product/molds/stainless-steel-bath-bomb-mold%2C-2-pieces/V000512.html
Molly says
Hello, I'm planning to make these with my Girl Scouts next week and I think they will love it! If we wanted to add epsom salts to the mix, when would we do that? Thanks!
Celine says
Hi Molly, that's a fun idea. you can add Epsom salts right in the beginning. May I suggest you use plastic bath bomb molds or Christmas ornaments if you have a group. That way they can take them home and take out of the mold the next day otherwise you would have to keep them somewhere over night. For younger kids it might be easiest to use a silicone mold similar to an ice cube tray where they can simply push the mixture into each cavity. Happy Tinkering 🙂
Kalli says
If I were to add Epsom salt, how much would I add? Do I need to change any of the other amounts to make it the right consistency?
Celine says
Hi Kalli, you can replace the cornstarch with Epsom salt.
Lorelei says
How many bath bombs does this recipe yield?
Celine says
two big sized bath bomb or 4 small bath bombs
Hazel says
can I use coconut oil from the grocery store?
Celine says
Absolutely
Dawn says
I see that many people use salt in their bath bomb recipes. I was wondering why you don't.
Celine says
Hi Dawn, I n order to make bath bombs fizz you really only need 3 ingredients: baking soda, citric acid and a form of liquid (witch hazel or water) in order to hold them together. Some people use salt to make them harder or add epsom salt for the added benefit. I have a bath bomb recipe on here with sea salt and one with epsom salt.
Minerva says
If I use sunflower lecithin instead of Polysorbate 80, how much should I use? should I use more wet ingredients since it's dry instead of wet like Polysorbate 80?
Celine says
I wouuld use 2 tsp, Amazon now sells one that is liquid. If you're using the dry form, use a little more witch hazel to get the consistency right.