How To Make Bath Bombs – DIY Bath Bomb Recipe

Have you tried making bath bombs and ended up with a soft crumbly mess? No worries! In this tutorial, I will show you how to make bath bombs step-by-step the RIGHT way and teach you several easy bath bomb recipes that can be customized to make pretty much any bath bomb you want!

the BEST DIY Bath Bomb instructions I've seen - these work just like LUSH bath bombs! #DIY #crafts #bathbombs

There are TONS of expert tips in this step-by-step tutorial, so it is pretty long. Here are a few quick links to answer any questions you might have: Here are the Best Bath Bomb Recipes, Bath Bomb FAQ (info on making bath bombs harder and fizzing, etc.), Labeling and Selling Bath Bombs, Bath Bomb Tools and Molds, Creative Ideas For Bath Bombs

Before we get into the DIY, let me tell you a story about Lush bath bombs. I visited one of the original Lush cosmetics stores in Toronto when I was about 19 years old and as soon as that fragrance hit me, I was in love! One of the best things about Lush is that they use natural ingredients. They are a cruelty-free, environmentally-friendly brand that just makes AMAZING products. To learn more about LUSH cosmetics and their amazing bath bombs and company, Click Here.

After using my first bath bomb from Lush (20+ years ago!) I began thinking about how to make bath bombs. I spent a lot of time testing recipes to get that perfect skin softening, relaxing, earth-friendly and creative bath bomb recipe (and this was before you could easily look them up on the internet btw!) When I perfected the recipe, I started a business selling them. The bath bomb recipe I developed is a versatile formula that can be used as a jumping off place for TONS of creative ideas. In my opinion, it is definitely the easiest and best bath bomb DIY recipe out there. 20 years later, I’m sharing it with you! 🙂

Bath Bomb DIY Tutorial

Bath Bomb Ingredients and Supplies

To make DIY bath bombs, you will need a few, inexpensive supplies. Some you might already have on hand.

  • Clean and completely dry glass bowl
  • clean and dry measuring cups
  • Something to mix with – a fork or whisk will work. You will be mixing mostly with your hands.
  • Bath bomb mold (a.k.a. mould) – CurrentlyI usethis Classic round aluminum mold for bath bombs , but you can absolutely use things you already have. (Read more about mold options here)
  • latex or rubber gloves
  • pipette for measuring drops of water or spray bottle
  • Oil-based fragrance (Choose a blend made for soap and cosmetics or mix your own blends using essential oils)
  • Powdered color for soap (here’s a good one) or for a more homemade bath bomb, just use food coloring.
  • Baking Soda, Cornstarch, Citric Acid.
  • Almond Oil

Bath Bomb Mold Options

Bath Bomb molds are inexpensive, and because you use them to press the bath bomb into shape and remove them to cure, you don’t need more than one to make a whole batch! A bath bomb mold must be hard – a floppy silicone mold in my opinion does not allow you to give enough pressure to form the shape. Also, choose a mold that isn’t too deep – if you use a cup or deep candle mold for example, it will be really hard to get the thing out! Here are some bath bomb molds I have used successfully:

How to make your OWN bath bomb molds from things you already have:

  • Muffin tin – this one is easy because you probably already have one!
  • Shaped metal or plastic molds for bath bombs – also available on Amazon
  • Plastic ornaments that open

DIY Bath Bomb Recipe

This bath bomb recipe that I developed and is made with baking soda, citric acid, cornstarch, and almond oil. It is the original one I used for bath bombs in my shop! The quantities listed here make one bath bomb, this recipe can be multiplied to make a batch of up to 12 at a time.

(Bath Bomb Ingredients to Make One Bath Bomb.)

  • 1/3 Cup Baking Soda
  • 1/6 Cup Cornstarch
  • 1/3 Cup Citric Acid
  • 10 drops Fragrance oil
  • 1/2 tsp Sweet Almond Oil or Coconut Oil
  • 10-20 drops Food Dye (a.k.a. food coloring) or Natural color pigment
  • 10 drops of water

(for bath bomb recipes without cornstarch or citric acid, click here)

**In case this is shared elsewhere, this post is originally from and can be found here:**

*Bath Bomb DIY Step-By-Step Instructions 

This part is the most important! If you just mix all of the ingredients, the water will activate the acid too much and start the chemical reaction. The method described here is very importantto making sure your bath bombs harden and fizz correctly.

Step 1: Mix The Baking Soda, Cornstarch, and Drops Of Water

Use your hands to mix the dry ingredients and add just a few drops of water. Do not add more than this or make the mixture wet. It will feel slightly cool to the touch.

Bath Bomb DIY TRICK - Mixing with your hands gives a better result!

Step 2: Mix In The Color, Oils, and Fragrance

Next, add the oils to coat the mixture before adding the citric acid. This helps control the activation of the mixture that creates fizz.

This Step-By Step Bath Bomb DIY is AMAZING!

Step 3: Add The Citric Acid

Once your mixture is well combined, add the citric acid. Work quickly to combine it evenly into the mix.

Bath Bomb DIY - Add Water

Step 4: Work quickly to add the water and mold immediately. With a two-part mold, you will overfill each side of the mold and press them very firmly together. If you are using a cupcake pan or tray, overfill the cavities and the push down to pack the ingredients.

Bath Bomb DIY - How to fill bath bomb molds!

Press hard (really smoosh it together!)

Once the ingredients are firmly packed together, carefully unmold. At this stage, your bath bomb will be firmly packed together but not hard yet, so handle it very gently once it is out of the mold.

How To Mold and Cure The Bath Bomb 

Once you have unmolded the bath bomb, handle your newly formed bath bomb carefully. It will take about 10 hours to become hard, so set it aside until it has cured fully. If you are packaging these, wait about 24 hours to be sure.

DIY Bath Bombs FAQ

How Do Bath Bombs Fizz?

Bath bombs are a mix of color, fragrance or essential oils, and an acid plus a base. When the acid is activated by water, it mixes with the base. This is what makes the fizzing happen when the ingredients combine (remember grade school chemistry experiments?) In bath bomb recipes, the acid is typically powdered citric acid. Citric acid is a kitchen ingredient commonly used in canning so it is easily found in the grocery store or health food store. The bath bomb base is made with ingredients you already have in your kitchen – baking soda! Baking soda is not just a base but a good-for-skin water softener. Your bath bomb will be mostly made of this!

What Makes Bath Bombs Hard? (A.K.A. Why did my DIY bath bomb fall apart!?)

If you have tried and failed at a bath bomb DIY before, I would bet it was because your bath bomb was too soft and fell apart. Maybe you had a bath bomb fail that fizzed out before you even used it! Part of what makes bath bombs cool and portable is the way they harden to form a ball. How do you get them to harden? To make bath bombs hard, you must mix a little liquid in, but not too much, and at just the right time. The mixing method I describe below is important to getting a professional looking bath bomb to give to friends or bath bombs to sell.

What Bath Bomb Mold or Press Do I need? 

Your mold needs to allow you to apply pressure on all sides of the bath bomb to smoosh it together, but you don’t need a press. This is why I don’t recommend silicone molds for bath bombs. (Small silicone molds are awesome for creating things to decorate your bath bombs though!) You will simply use your hands to press your filled mold, and once the ingredients cure and dry (about 5-24 hours,) it will become hard. See Bath Bomb Molds for recommended molds you can buy.

Where to buy bath bomb molds? 

Traditional bath bomb molds are available on Amazon. You can buy one, or a kit that has several sizes. Check out all of the bath bomb options you can buy here: Where To Buy Bath Bomb Molds

Why is the bath bomb color not even?

Using a powdered pigment for soap or cosmetics will give a more even color. To evenly disperse food coloring, mix with a mixer or your hands. A whisk can’t seem to break up the color enough in my opinion. Really mush it up with your fingers for the best result.

Other Bath Bomb Mold options I have used:

There are many inexpensive two-part molds available for bath bombs in crafts stores and on Amazon. You can find the classic round sphere molds in many sizes and tons of shapes like donuts, shells, hearts, and stars.

  • Muffin Tins – I used to use two muffin tins to press 12 bath bombs at a time. I’ve also made smaller bath bombs in muffin tins by just using one and pressing the mix evenly from the top of each cavity with my hand.
  • Two-Part Plastic Ornaments – These work great for a couple of batches, but will probably break at some point. Fine in a pinch or to re-use something you already you have.
  • Cake and Chocolate Molds
  • Candle Molds – make sure these are very shallow or you will have a hard time getting them out. Also be careful of the edges of these molds – sometimes they are a thin metal which might cut you if you press on them very hard with your hand.
  • Ice Cube Trays – I’ve used these to make smaller bath bombs and fizzing peppermint foot soak. They work great!

How Many Bath Bomb Molds do I need?

If you are working by yourself, you will only need one at a time. Bath bombs are unmolded right after you press them with your hands, so you don’t need more than one mold at a time unless you are making different shapes. The classic bath bomb round mold is totally versatile – you may need only one.

Glitter For Bath Bombs and Other Solids

Glitter is a great addition to bath bombs, but do NOT use regular craft glitter. It is plastic, and that extra plastic in our water systems causes all kinds of issues. Edible glitter and natural mica are better choices. Same goes for solids – anything you add to a bath bomb will be flushed down the drain, so be sure it is natural and safe for water systems.

How Do I Make Bath Bombs That Change Water Color?

To make bath bombs color the water, you need to add enough food coloring or pigment to color the several gallons of water that you typically have in a bath. When I am designing a bath bomb experience, sometimes I will do a test bath and add drops directly to a full bathtub.

How To Use a Bath Bomb

This is useful if you have never used a bath bomb before or if you need to explain it for a bath bomb label.

  1. First, fill your bathtub as you would normally.
  2. Next, drop your bath bomb into the full bath.
  3. Wait until it is fully dissolved before getting in to allow all of the ingredients to mix into the water evenly.
  4. Relax and Enjoy!

Selling Bath Bombs and Labeling Requirements 

If something is identified as a cosmetic by the FDA, it is subject to stricter rules regarding labeling. Is a bath bomb a cosmetic? The FDA defines a cosmetics as “articles intended to be rubbed, poured, sprinkled, or sprayed on, introduced into, or otherwise applied to the human body…for cleansing, beautifying, promoting attractiveness, or altering the appearance.” from the FDA’s website.  

Generally, this suggests that a bath bomb would often qualify as a cosmetic, especially if you add ingredients intended to benefit skin health or appearance like moisturizers.  What does this mean? If you are selling your bath bombs you should plan to include a label or something with the product that list ingredients. Afterall, even if it’s not required, I would definitely want someone who had an allergy to avoid using something that might be problematic for them. If the ingredients aren’t listed, how could they know? Read more about requirements on the FDA’s website. 

Other Bath Bomb Recipes and Substitutions

If you have an allergy to one of the ingredients in the basic recipe or just don’t have something on hand, here are some other recipes you can try.

How To Make Bath Bombs Without Citric Acid

Bath Bomb Recipe 2 (Without Citric Acid)

This recipe uses Cream Of Tartar instead of Citric Acid.

  • Baking Soda
  • Cream Of Tartar
  • Fragrance oil
  • Sweet Almond Oil or Coconut Oil
  • Natural color
  • Tiny bit of water*

Bath Bombs Without Cornstarch

You can replace the cornstarch with the same amount of baking soda. It works just fine, just maybe slightly less fizzy when you use the bath bombs because it changes the acid to base ratio.

How To Make Bath Bombs For Kids

Kids can make bath bombs just like adults do! An adult will need to help with adding fragrance and the molding part, but the ingredients are safe.

How to make Bath Bombs Foam

Bath bombs foam with the addition of a soap. Many use SLS powder, but for a natural alternative, you can experiment with adding natural shredded soap or a natural herb that suds.

Bath Bomb Recipe 3 (how to make bath bombs with epsom salt)

This recipe is from the little pamphlet in the bath bomb mold I purchased. It’s also in grams for those who like to weigh ingredients.

  • 250g Baking Soda
  • 120g Citric Acid
  • 120g Cornstarch
  • 120g Epsom Salts
  • 3 Tsp water
  • 6 tsp essential oils
  • 3 tbsp vegetable Oil
  • 1-2 drops food coloring

Bath Bomb Recipe 4 (Without Citric Acid or Cream of Tartar)

This recipe has no fizz but is great for adding fragrance and color to a bath. It is higher in skin-softening oil too and is a soft tablet – often called a bath melt because it literally melts in the bath.

Bath Bomb Recipe 5 (Without Almond Oil)

If you can’t find almond oil or simply prefer to use coconut oil, try this recipe.
(makes about 3 bath bombs)

  • 1 cup citric acid
  • 1 cup baking soda
  • ½ cup cornstarch
  • ½ cup melted coconut oil
  • 8-10 drops of essential oil(s)
  • Food coloring (optional)

Creative ideas for bath bombs

Now that you have mastered making a DIY bath bomb, it’s time to get creative! The thing that makes bath bombs so fun to use it that they create a multi-sensory experience when used. So think about colors, scents, shapes, names, and other additions that will enhance the experience for the user.

  • Mix scents for effect or based on a theme
  • Add glitter and aromatic solids – bath tea in cheesecloth or ring in plastic capsule
  • Add surprises
  • Make a Milk Bath Bomb
  • Packaging
  • Rules for selling bath bombs
  • eco and drain-friendly glitter
  • make a soap bomb

Other Bath Bomb Designs Here are some other bath bomb ideas to get you thinking about cute bath fizzies you can make at home:

  1. The Starfish Bath Bomb
  2. Rainbow Sherbet Bath Fizzies
  3. DIY Bath Bomb Recipe from Skip To My Lou
  4. Peppermint Foot Bath Fizzies
YES! The best bath bomb diy instructions I've seen! Plus a recipe for LUSH bath bombs. #DIY #BATHBOMBS #crafts