How to Make Bath Bombs

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Learn how to make bath bombs with our easy-to-follow bath bomb recipe and step-by-step tutorial! DIY bath bombs are a ton of fun to make and are a fantastic homemade gift idea!

purple bath bombs on floral background

Have you been wanting to learn how to make bath bombs, but feel overwhelmed by all of the different recipes and information out there?  We’ve got you covered! Today we’re sharing our most favorite bath bomb recipe along with ALL of the information, tips, and tricks to ensure that your bath bombs will be successful from the start! 

We can all enjoy taking a nice relaxing bath and reading a good book to de-stress (when you get the time!). The best part is watching mesmerizing bath bombs fizz around you while inhaling your favorite essential oils and feeling your skin turn into butter as you melt back into the warm water. Top it all off with a nice glass of wine, and my weekend is made!

Bath bombs are easy for the at-home, crafty entrepreneur to make and are a great gift idea for friends, family or anyone! This tutorial will break it down into simple, step-by-step instructions so you can easily craft your own bath bombs.


DIY HOMEMADE BATH BOMBS

Use our easy homemade bath bomb recipe and learn how to make DIY bath bombs with our step-by-step tutorial!

blue bath bomb fizzing in bath tub water

What is a Bath Bomb?

A bath bomb is an effervescent explosion of colorful fun in your bathtub! Used to add color, foam, fizz, and bubbles to your bath time experience, many bath bombs also contain oils and butters that moisturize and nourish the skin.

Essential oils, salts, and clays may also be added to the bath bombs to increase the detoxifying properties and add health benefits. It’s like creating a luxurious spa-like experience in your own home!

How to Make Bath Bombs

pink bath bombs on blue platter

Bath Bomb Ingredients:

Knowing the role that each ingredient plays in your bath bomb recipe is important if you want to be successful. Bath bombs can be a little finicky to make sometimes, but with a little knowledge, you’ll know exactly how to tweak your recipe to suit your climate and environment for foolproof bath bombs every time!  

The most basic bath bombs can be made by simply combining baking soda, citric acid, and a binder; however, we’ve found that the BEST bath bombs include a few more ingredients. This list here will help you know which ingredients are irreplaceable and which ones can be omitted if desired. 

Bath bomb ingredients on dark wood background

Not all of these ingredients are used in our Best Bath Bomb Recipe below, but for your own future recipe creation, these are all important to know! 

BAKING SODA 

Sodium bicarbonate, more commonly known as baking soda, is the main ingredient in bath bombs. Scientifically known as a “weak base” which will result in a fizzing acid-base chemical reaction when combined with citric acid. Baking soda softens the bath water and leaves your skin feeling smooth and soft. 

CITRIC ACID

Citric acid is the second key ingredient in bath bombs. It is a naturally occurring “weak acid” derived from citrus fruits which promotes the fizzing reaction when combined with baking soda. 

CORNSTARCH

Cornstarch is a popular filler ingredient that is often used in bath bombs as a thickening and hardening agent. Too much corn starch can reduce the fizzing action, though, so don’t get too heavy-handed! 

CREAM of TARTAR and CLAYS

Cream of tartar and clays are also used to harden bath bombs. 

SODIUM LAURYL SULFOACETATE (SLSA)

SLSA is a naturally-derived (from coconut and palm oil) surfactant that creates thick and luxurious foamy bubbles during the fizzing process.

SALTS

Salts are included in bath bomb recipes for their purported health benefits. Epsom salt, reported to soothe sore muscles and increase well-being, is the most commonly used salt, but sea salt and pink Himalayan salt are also frequently used due to their reputed detoxifying properties.

Note: Salts attract water and can occasionally start the fizzing reaction prematurely, so they should be included in minimal to moderate amounts only. Grinding coarse salts to a fine powder will produce the best results and smoothest finish on your bath bombs.

OILS

Oils are used to add moisture to the bath bomb recipe and to bind the mixture together. All oils have moisturizing properties that hydrate and soften skin, and different varieties of oil also lend various additional benefits. The most popular oils to use in bath bombs are sweet almond oil, avocado oil, coconut oil, grapeseed oil, and jojoba oil. Caution: Bath bombs that contain oils may make your bathtub slippery!

BUTTERS

Butters add moisturizing properties to your bath bombs to make skin extra smooth and silky, and some butters may even help harden bath bombs as well. Commonly used butters include avocado, cocoa, coffee, mango, and shea. Caution: Bath bombs that contain butters may make your bathtub slippery!

FRAGRANCE OILS and ESSENTIAL OILS

Essential oils are naturally derived oils that can add both fragrance and reported health benefits to your bath bombs. Fragrance oils are generally synthetically created, cost far less than essential oils, and are available in an HUGE variety of scent options.

COLORANTS

I like to use cosmetic micas to color my bath bombs (Mad Micas carries some super awesome bright colors!), but other colorant options include FDA-approved lakes and dyes which must first be “bloomed” into the baking soda before beginning your recipe. I do NOT recommend using drops of food coloring in your bath bombs as it can stain skin and the bathtub. 

POLYSORBATE 80

If you do opt to include colorants, especially micas, adding a bit of Polysorbate 80 to the recipe will help the color disperse more evenly throughout the water and prevent it from leaving a ring around the bathtub. 

WITCH HAZEL

Witch hazel is the most commonly used liquid binder for bath bombs, but you can also use a mixture of water and isopropyl alcohol if you prefer (note: using alcohol as a binder may result in drier and more crumbly bath bombs depending on your climate). A scant amount is used to bring the mixture to the proper consistency and help bind the ingredients together.

Bath Bomb Molds

Bath bomb molds will make it easy to shape your creation into a perfect sphere, or any shape you desire! You could also use ice cube trays, muffin tins, or silicone molds of any shape. Just make sure you firmly pack your completed mixture into whatever mold of your choice.

How to Make Bath Bombs - white bath bombs on coral background

Step-by-Step DIY Bath Bomb Tutorial

Let’s learn how to make bath bombs! This easy-to-follow recipe and tutorial will have you creating professional-looking bath bombs in no time!

Sifting baking soda for bath bombs

Start by using a large mesh strainer to sift the baking soda into a large mixing bowl and use a spoon to break up any clumps. Sift the citric acid into a second small bowl and set aside for later. 

Adding dry ingredients to a mixing bowl to make bath bombs

Add the remaining dry ingredients (minus the citric acid) to the baking soda bowl and mix well. 

Bath bomb dry ingredients in aqua stand mixer

I like to use my mixer to help make sure that all of the ingredients are thoroughly incorporated, but a good old fashioned spoon works just as well (it just takes a little longer!).

Pouring wet bath bomb ingredients into dry bath bomb recipe mixture

In a small container, mix together all of the liquid ingredients. Stirring constantly, slowly add the wet ingredients into the dry mixture and mix until completely combined. Stir quickly to ensure that the fizzy mixture doesn’t start to activate when you introduce the liquids! 

spraying bath bomb mixture with witch hazel

With a spray bottle, lightly spritz the mixture with 2-3 quick sprays of witch hazel (or a mixture of water + isopropyl alcohol) and mix well. 

testing the bath bomb mixture consistency with hand

Test to see if the mixture is a moldable consistency – it should feel just very slightly damp and kind of like kinetic sand. 

testing the bath bomb mixture firmness in hand

If the mixture holds together after being squeezed and then lightly dropped back into the bowl, it is ready to mold. If the mixture is too dry, spritz with 1-2 more sprays of witch hazel, stir, and repeat as necessary until the mixture reaches the proper consistency. 

Overfilled halves of a metal bath bomb mold

Lightly pack the bath bomb mixture into both halves of the mold and generously overfill each side of the mold. 

molding a bath bomb in a metal bath bomb mold

Press the halves firmly together and gently brush away any excess from the sides of the mold.

Half molded white bath bomb

When unmolding round bath bombs, remove half of the mold at a time and allow the bottom half of the bath bomb to rest in the other half of the mold while the top half of the bath bomb dries. This step ensures that the bottoms of your bath bombs stay rounded and don’t flatten out. 

Flip the mold to the opposite side of the bath bomb after an hour and then unmold completely after 2 hours. Allow to dry completely for 24–48 hours. 

Bath bombs drying on egg crate foam

Note: I like to dry my DIY bath bombs on egg crate foam to help keep their rounded shape and to allow air to circulate freely around the bath bomb to help it thoroughly dry. This photo shows halfway unmolded bath bombs, but I also use the egg crate for drying once they have been completely unmolded!

Rainbow sherbet bath bombs in a bowl

Once you’ve mastered making a single-colored batch of bath bombs, make several batches and experiment with different colors and fragrance combinations! The possibilities are truly endless! 

Easy DIY Bath Bomb Recipe

pink bath bombs on blue platter

The BEST Bath Bombs

The best bath bomb recipe that will produce lots of fizzy fun and add a light layer of colorful foamy bubbles to your bath!
5 from 3 votes
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Yields: 7 Bath Bombs

Instructions:

  • In a large mixing bowl, thoroughly combine the baking soda, cream of tartar (or kaolin clay), SLSA. Stir in mica colorant if desired until completely combined.
  • In a small container, combine the oil, fragrance/essential oil, and Polysorbate 80 (if using).
  • Stirring constantly, slowly mix the liquids into the dry ingredients until they are completely combined.
  • Add citric acid to the mixture and stir until it is fully incorporated.
  • Test to see if the mixture is a moldable consistency – it should feel like slightly damp sand and hold together when squeezed in your hand.
    If the mixture is not quite wet enough to mold, spritz two to three times with a spray bottle of witch hazel and mix well. Repeat as necessary until the proper consistency is reached.
  • Fill both halves of the bath bomb mold with the bath bomb mixture, making sure to overfill both sides of the mold just a bit. Press both halves of the mold firmly together.
  • Carefully release the bath bomb from the mold (tap the mold lightly with a wooden spoon if needed) and allow it to dry completely for 24-48 hours depending on the temperature and humidity of your location.

Notes:

The amount of fragrance oil and/or essential oil that will need to be added to your bath bomb mixture will vary widely depending on what you are using. Generally, fragrance oil can be added by the 1/2 teaspoon until the desired amount of fragrance is reached. Essential oils are often far more potent than fragrance oil, so we recommend adding 15-20 drops of essential oil to each recipe to start and then adding more in 5 drop increments until the desired level of fragrance is achieved. 
Did You Make This?Mention @HeidiKundin or tag #hihmakersclub on Instagram to show off your awesome work! ♥

I hope that after reading all of this “How to Make Bath Bombs” information that you’re feeling super confident and ready to start making your own DIY bath bombs! Happy crafting! 

For even MORE bath bomb tips, tricks, and recipes, be sure to check out our book, Homemade Bath Bombs and More

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38 Comments

  1. can I replace the cream of tarter and use bentonite clay by chance?
    Second question wondering if maybe you can help?! I’m in my first week of making bath bombs and have a huge metal bowl of uhh how should I put it…. Fail recipes… what can I do with it ? Or should I just toss it out it’s already everything in it just it’s dried now.

    1. You can absolutely swap out the cream of tartar for bentonite clay! Don’t toss out those crumbly “failed” recipes, though! Place the dust and crumbs into a pretty zipper bag and call it “Fairy Dust” – it will still fizz and bubble up in the tub, and it’s even easier to control the amount that you use in your bath this way! If you search “Bath Fairy Dust” on Etsy, you will see lots of great examples for fun ways to package it up and salvage it! 🙂

    1. Hi Aya, the SLSA adds more of a light foam to the bath with clusters of small bubbles, and the CB adds larger and more bubble bath-like bubbles to the tub. 🙂

  2. 5 stars
    Hello Heidi! I love your DIY bath ideas. I just purchased your “Homemade Bath Bombs & More” Book. I love the color of your KitchenAid Mixer. May I ask what the name of the color that is shown in your book and website. Thank you for taking the time to read this, I really appreciate it. 🥰 Stephanie

  3. Thoughts on following your recipe but changing “1 1/2 Cups of Citric Acid” to “1 Cup Citric Acid” and “1/2 Cup Espom Salt” …. Does this work?

    1. I think you could definitely give that a try, Jena! The success of your recipe modifications will depend a lot on your own climate and environment (temperature, humidity, etc.), but this swap definitely could work. I would recommend using fine grain Epsom salt for best results. Do note, though, that you may end up with slightly less “fizzy action” if you reduce the citric acid. If you try it, let me know how it works out for you! 🙂

  4. Hi!
    Followed all the steps and left them to dry in the bottom mold.
    But now they are stuck in the mold and not coming out. An idea why?

    Thanks
    Lubna

    1. Hi Lubna,

      You always want to remove the bath bombs completely from the molds to dry as the mixture can expand a bit during the drying process (which can cause them to get stuck inside the molds like that). Our directions recommend that you “remove half of the mold at a time and allow the bottom half of the bath bomb to rest in the other half of the mold while the top half of the bath bomb dries…flip the mold to the opposite side of the bath bomb after an hour and then unmold completely after 2 hours. Allow to dry completely for 24-48 hours.” So, next time, just be sure to remove them from the mold completely after an hour or two so they don’t get stuck! 🙂

    1. Hi Nicola,

      You can absolutely tweak the recipe to your liking including adding Epsom salts. I recommend using fine grain (or ground) Epsom salts for best results, starting with 1/4-1/2 cup at a time. You may need to slightly increase your oil as well to compensate for the additional dry ingredients. 🙂

  5. 5 stars
    This was the first bath bomb recipe I tried so I didn’t understand the horror stories about failed bombs. It wasn’t until I tried other recipes that I realized I had hit the gold mine of recipes my first try and came right back to this one. Perfect for humid climates and beginner. Bath bombs came out hard, fizzed and foamed perfectly. My toddlers love these

    1. We actually have a bubble scoop/bar recipe and tutorial coming up really soon! In the meantime, you can also find the recipe in my book, Homemade Bath Bombs & More.

      Our bubble scoop recipe makes a TON of bubbles, and it calls for equal parts of baking soda and SLSA, so if you just want to amp up the amount of bubbles in your bath bomb, you can add more SLSA (though you may also need to add more oil to offset the wet:dry ratio if you use a lot). You can also cut the oil in the bath bomb recipe in half and substitute the same amount of cocamidopropyl betaine instead – the CB produces lots of bubbles as well! 🙂

  6. I used this recipe recently and it’s great because it uses less SLSA than other recipes. But in my opinion gives enough of the same effect of bubbling and fizzing.

  7. The ingredient list is fine, however, the recipe does not tell you how much to put in; such as, how much baking soda, etc. do I put in at a time.

  8. I wanted to use this recipe as a bath crumble, do I still mold it and then break them apart? Or do I forego the molding and put the mixture in an airtight container to dry out? What would you recommend?

    1. Also if I wanted to add more SLSA, do I need to change anything else on the recipe or just leave it the same but have more SLSA?

      1. If you’re adding more SLSA to actual bath bombs, you may want to also add an extra spritz of your binding spray if the mixture seems too dry to mold. If you’re adding more to a bath crumble powder mixture, you can just add more as desired without the need to compensate with any additional moisture.

      2. Would I need to mould them if I’m using it as a bath crumble or do I just skip that step?

    2. Hi Jessica! When I make bath crumbles, I generally still mold bath bombs with them initially, but I just pack the molds loosely so that they’ll be easier to crumble apart. I do it that way because I prefer to create a few larger chunks in my bath powder mix, but you can also skip the molding if desired. I would suggest spreading your bath bomb mixture all out on a cookie sheet and allowing it to dry for a few hours in open air before moving it to an airtight container. 🙂

  9. I’ve been using coconut oil, polysorbate 80, and either mica or food coloring. Doesnt seem to matter adding the P80 because my color and oil always floats to the top and sticks to the sides. Do you think it could be the coconut oil??

    1. Hi Amanda, I don’t think that the coconut oil is causing the issues (are you using regular coconut oil or the always-liquid fractionated coconut oil?). How much Poly 80 are you adding to your recipe? The P80 should help the mica disburse evenly in the water vs floating on top (food coloring can also cause this issue and is not recommended for use in bath bombs), but you may need to add a little more depending on how much mica is also in your recipe. If you do add more P80, be sure to reduce the oil amount just a bit as well so that the mixture doesn’t get too wet. 🙂

  10. Your bath bombs are beautiful. I followed your recipe to a t, they looked beautiful but I had a problem after I took them out to dry.
    I did not follow your instructions for drying, sorry. Will do the next go round. Anyway after they were left to dry the tops became somewhat bumpy, no longer smooth. would love to show you a picture.

    1. Hi Lorna, I’m so glad you gave our recipe a try! As I said in the post, bath bombs can be very finicky, and the recipe will likely need to be tweaked a bit to suit your environment. For me, I am in Northern California where we have minimal humidity, so I may add a little more moisture to my bombs that in necessary in other places and climates. That said, the bumpy surface is generally a result of your mixture being just a bit too wet – the excess moisture begins to activate the bath bomb just a tiny bit, and you’ll end up with “warts” where the gasses try to escape from the bath bomb (in essence, the bomb is VERY slightly fizzing somewhere inside, and the air created is trying to escape the bath bomb via those tiny bumpy areas). Next time, try decreasing the oil in the recipe by about 1/4 to 1/2 tbsp, and make sure that you’re not adding TOO much more moisture with the witch hazel (or alcohol) spray as well. It should JUST stick together when you give it the squeeze test. Just keep practicing, and you’ll find the perfect ratio for your climate and environment in no time! 🙂

  11. Hi was wondering if i could add a 1/4 cup of cornstarch with the cream of tar. What would be the outcome ? Would it make it extra hard.

    1. Hi Nandi! It really depends on your climate and environment, so I can’t say for sure – bath bombs are VERY different in different environments, so the ingredients won’t always cause the same results from one place to another. In some instances, cornstarch will make the bath bombs harder, and in some instances it can actually make them softer. In all cases, cornstarch will slow the reaction of the baking soda/citric acid, so it will prolong the fizzing action. 1/4 cup should be fine, but make sure not to add TOO much or it can stall and hinder the fizzing action altogether. My best suggestion would be to experiment and give it a try and see how it works for your specific environment! 🙂

    1. You can omit the SLSA if desired. Its purpose is to add more bubbles/foam to the bath bomb, but it’s fine to go without it! 🙂

  12. This receipe is great! How can you make the bubbles last longer. Seems like they were gone by the time all the fizz ran out?

    1. Hi Danielle! If your bubbles are running out too quickly, I would suggest doubling the amount of SLSA you use in your recipe. Different climates may require a bit of tweaking to this recipe to get your ideal results. You can also add about 1/2 or 1 tsp of cocamidopropyl betaine to your recipe to produce a LOT of bubbles, however, you will want to adjust the amount of oil that you use to compensate for the additional liquid so the mixture doesn’t get too wet. 🙂

    1. Yes! The SLSA is just added to give your bath bomb more bubbles, but the recipe will still work if you omit it. 🙂

  13. I always have the hardest time with bath bombs. They always fall apart. I’m going to try your recipe instead. 😀

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