Hidden Color Bath Bombs

Here’s a fun idea for a colorful surprise hidden inside a bath bomb. This tutorial is perfect for getting kids to take a bath, because there’s enough colorant in each bath bomb to color the bath water. And since you can’t see the color until the bath bomb is activated, you have to be in the bath to get your surprise! I originally came up with this idea … well, you’ll have to see why this weekend. =)

Hidden Color Bath Fizzy

Scroll down to the bottom of the post to see a mini fizzy coloring water!


1.5 cups Sodium Bicarbonate (Baking Soda)

1 cup Citric Acid

12 mL Baby Powder Fragrance Oil

Teal LaBomb Colorant

Witch Hazel (in a spray bottle)

Droppers with Suction Bulb

2-3 Stainless Steel Bath Bomb Molds

Mesh Strainer

Click here to add everything you need for this project to your Bramble Berry shopping cart!

OPTIONAL MOLD PREP: To aid in the unmolding of the bath bombs, add 5-10 drops of Cyclomethicone inside each half of the Stainless Steel Bath Bomb molds. Swirl it around so that there is a nice coat covering the inside of the molds. Set the molds on paper towels in a way that allows the excess Cyclomethicone to run out. You want just the thinnest coat of Cyclomethicone inside the molds.

Adding Cyclomethicone

ONE: Place the mesh strainer over the top of a bowl. Measure the Sodium Bicarbonate and Citric Acid and pour into bowl through the strainer. Work any clumps through the strainer. TIP: Citric Acid and Sodium Bicarbonate (Baking Soda) can tickle your nose, so you might want to wear a mask if you’re sensitive.

TWO: Add 12 mL Baby Powder Fragrance Oil to the mixture. Using your hands, mix until the fragrance oil is not longer causing clumps. NOTE: If your child is very sensitive to fragrance, keep the fragrance out or decrease the amount to only 6 ml. Some children find fragrance overwhelming.

Adding Fragrance Oil

THREE: Spray the mixture with 5-10 spritzes of Witch Hazel and mix in well. You want to add just enough moisture so that the mixture holds together, but isn’t soggy. Keep adding Witch Hazel until the mixture reaches a consistency that you like. I know my mixture is ready when I squish some fizzy mixture in my hand and it mostly holds together. TIP: For great live-action shots of the ideal consistency of bath bomb mix before putting it into a mold, check out our latest Soap Queen TV with guest Jeanee Duvall of Dirty Laundry! It’s at minute 3:30.

Spritz Witch Hazel

FOUR: Fill one half of each of the Stainless Steel Bath Bomb molds with bath bomb mix, pressing the mix as compact as possible. Make a crater or divot with your thumb, about 1/2″ deep with about 1/2″ on all sides in the center of the mold. Add 10-15 drops of Teal LaBomb into each divot. Fill the divot with more bath bomb mix, and create a slight mound in the center of the mold.

Color in divots

FIVE: Fill the other half of each of the Stainless Steel Bath Bomb molds all the way with bath bomb mix, also mounding the center slightly. Press two halves of the mold together, one colored half and one uncolored half, until there is no gap between between the two halves.

SIX: Waiting no longer than about 5 minutes, unmold the bath bombs by slowly twisting the mold halves and removing one half of the mold. If the second half of the mold is not quite ready to release yet, wait 5-10 minutes and then gently tap the mold from behind.

TIP: Take a peek at this bath bomb video for tips on unmolding the Stainless Steel Bath Bomb molds.

What's AM going to do with those tiny fizzies?

This idea also works for coloring smaller amounts of water. Cut the recipe in half, and use a small mold like the Petite Bendy Star Mold. Use the same technique of filling the mold half full, but use just one or two drops of colorant per cavity. One tiny bath bomb with two drops of colorant will nicely color about a cup and a half of water. Why did I test out such a small amount? Check back this weekend as I reveal some super exciting Bramble Bump news!

Coloring the Water

Click here for a printable PDF of this tutorial.

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  1. ginger says

    I’ve been wondering with bath fizzies in general, can I add coconut oil? I’ve seen people use olive oil and almond oil. Is it worth a try?

    • Kelsey says

      Hi Ginger!

      Because coconut oil is solid at room temperature, it may make those fizzies a little harder than usual. You may want to start out with 1/2 tsp. per cup of bath fizzy mixture and see if you like the consistency. Hope that helps! Let us know how it goes. :)

      -Kelsey with Bramble Berry

      Coconut oil: http://www.brambleberry.com/Coconut-Oil-P3196.aspx

  2. Emma says

    I’m keen to make these bombs but I only have one mould. Can I still make up all the mixture and then maybe cover it or will it go yuck in the time it takes for the bomb to set? Should I just reduce the amount for one bomb at a time instead? thank you so much!

    • Kelsey says

      Hi Emma!

      I would recommend only making enough to fill your mold so it doesn’t start to clump or harden.

      Or, you can mix up all the powders and hold off adding the liquid (fragrance, color, Witch Hazel) until just before molding. :)

      -Kelsey with Bramble Berry

      • Emma says

        That’s what I thought but I wanted to check before I ruined a whole heap of mixture! I might have to invest in a few more moulds I think. Thanks so much for replying Kelsey!

  3. Chris says

    Hi, I’m trying to create a bath bomb similar to a dragons egg that lush sells. Inside the bath bomb is a yellow substance that looks like egg yolk which I expect is glycerine mixed with soap colorant and some glitter. I have seen on your site that you sell products for a hidden colour bath bomb but the delivery costs are enormous.

    Do you have any suggestions for creating bomb colorants that are liquid.


    • says

      Hi Chris!

      That bath bombs sounds really interesting, I have never heard of anything like that before! I did a little research, and it looks like glycerin is not listed in the ingredients. Containing any kind of liquid inside a bath bomb would be very difficult (maybe impossible), because it could set of the fizzy reaction of the baking soda and citric acid. I would guess that there product is a variation of this tutorial. It could even by a “bath bomb inside of a bath bomb” type of product, where the bath bomb inside is made of a different color with added glitter. I hope this helps, sorry I do not know more about that particular product! :)

      -Amanda with Bramble Berry

    • says

      Good morning, Elaine!

      The liquid glycerin is a bit thicker and would probably stick to your bath bombs. If you have any mineral oil, you can also try that as a way to coat your stainless steel bath bomb molds for easy use. I hope this helps! :)

      -Becky with Bramble Berry

      • Elaine Lombardo says

        Hi Becky, I used the tiniest bit of glycerin and it worked fine for me. I was wondering, what type of colorant can I use to color the bath water? And how much of it would I need to use to color the whole bath like in the small amount example shown here? Personally I like to use clays but if they won’t color the water I’ll go with whatever suggestion you recommend. Thank you! :)


        • says

          Good morning, Elaine!

          We are so excited that this project turned out so well for you and if you were able to get some pictures, we’d love for you to share them with us on Bramble Berry’s Facebook page.


          The amount of colorant listed in main the recipe above was enough to color the bath water in our tests (about 10-15 drops per fizzy). The smaller bath bomb that colored the water was just a scaled-down example. If you follow the main recipe you should get colored bathwater!

          Bath Bomb Dyes: http://www.brambleberry.com/Bath-Bomb-Dyes-C50.aspx

          Clays aren’t going to give the brightest and intense colors in the bathtub, but you can try them out! Be sure to let us know how your batch turns out.

          I hope this helps! Let me know if there is anything else we can do for you. =)

          -Becky with Bramble Berry

  4. says

    Thanks Becky, the discussion is on the teach soap forum under the topic of toletries ,lotions ect. posted by soapbuddy and the topic is Please don’t use wilton colorants for bath fizzies. Thank you so much for investigating this info.

    • Anne-Marie says

      Just read the thread and while Wilton food colors technically have been approved for us in food, they do have some extra ingredients you don’t need in the bath fizzies. And, you’d want to cross reference all those ingredients to make sure they’re on the FDA list for approved colorant additives (including the colorant itself – there’s a better than good chance that it’ll be on there; often if something is approved for food, it’ll usually be approved for use in soap). I hope this helps! =)

  5. says

    Hi Becky , on the subject of colorants, I noticed on the forum a discussion on wilton colorants and that they are in violation for use in bathbombs or bath cupcakes ect. can you please shed some light on this? And what is the difference between your La Bomb colorants and Wilton FD & C colorant. Everytime I feel like i’m moving forward there is another obstacle to set me back and make me insecure about my business. :(

    • says

      Hi Carolyn!

      The difference between our La Bomb colorants and the Wilton colorants is that there are a couple extra ingredients in the Wilton dyes. But, I’d love to see the discussion you are talking about so we can investigate this claim a little more! Thanks. =)

      -Becky with Bramble Berry

    • says

      Hi Denise!

      As long as your bath fizzies are kept in a cool and dry area, you can keep them up to at least a year before use. =)

      -Becky with Bramble Berry

      P.S. And by ‘dry’, sometimes that means putting inside sealed Ziploc baggies. A lot of places have humidity fluctuations throughout the year.

  6. says

    I love the cyclomethicone idea! You always come up with such fabulous ideas! I haven’t made bath bombs in a few years, but I now have a lot of free time on my hands. I may try your recipe this week!

  7. Marielitos Archila Garcia says

    Love Bath Bombs!!! Thank you so much for share this great idea with us!!!

    I can’t wait to know if you are having a baby boy or a baby girl!! lots of love for you and your beautiful family!


    Aromas y Colores :)

  8. Gabi says

    Hi! I can’t buy witch hazel from Bramble Berry, because I live in Hungary! :( :)
    Which can be used instead of this product?
    Thanks, Gabi

  9. Nickie says

    OOOH GOODY! I can’t wait to hear (well, actually read) the news :) I’M SO CRAZY EXCITED!!! I wish that I could jump through my monitor & hug you right now 😉 …that’s how excited I am.
    Will try this for the kids that we watch… they’re gonna flip lol


    • Anne-Marie says

      We are too! We’re doing a big balloon reveal tomorrow night for me, Chris and Jamisen. I’m giving the sealed envelope to a friend to get balloons in the correct color. And then, we’ll open the box and find out. We’ll announce this weekend after we’ve told our folks =)

      • Nickie says

        So you didnt know what the gender was? You had it put in an envelope & gave it to a friend, she gets the balloons, puts them in a box, you open it, & all of you then find-out? Just so I can understand :) Congrats again! ~Nickie~

  10. Rachel says

    I was actually thinking of doing this but with glitter! Not very practical I think, seeing as how its hard to get rid of glitter, and I dont know if anyone wants to sit in a glittery mess.

    • Anne-Marie says

      Lush makes a Glitter Bomb (or at least, they did) that was made for precisely that reason – glitter in the tub. So, you’re in good company with your idea.

    • Anne-Marie says

      =) We don’t know what we’re having yet. We’ll find out tomorrow night actually. But yes, we are testing blues and pinks …