The secret ingredient for making bubble bath bombs is SLSa or sodium lauryl sulfoacetate. This nontoxic surfactant is derived from palm and coconut oil. It helps water molecules bind to soap grease and stretch into a bubble formation. However, do not confuse SLSa with SLS, or sodium lauryl sulfate.
Homemade Bubble Bath Bombs
Bubbles are made from a soap-water-soap sandwich. Now normally, grease and water don’t mix–in fact, they separate. So how do you get soap grease to adhere to water? The secret is using a chemical agent called a surfactant. This ingredient helps water molecules become stretchy, so much so, that they will affix to the soap molecules and stretch into the shape of a bubble.
Commonly used surfactants for bubble bath bombs include SLSa and SLS. But these ingredients are alike in name only. Unlike SLS which can irritate the skin, SLSa is free of phosphate, non-toxic, and gentle on skin. Although SLSa is more expensive than SLS, for homemade bubble bath bombs, SLSa is what you want.
For Awesome Bubbles, Proportions Are Key
No matter what bath bomb recipe you’re using, you can turn it into a bubble bath bomb if you understand how to make SLSa work correctly. The trick is to understand the proportions of the ingredients that you need. You’re going to want to use 1/2 cup SLSa with 1 cup of Epsom salt and 2 cups of baking soda (sodium bicarb). You need these proportions to make it work correctly.
Too much SLSa and your bath bombs will crumble in your hands once they dry, before you even throw them into the bath. If you use too little SLSa, your bath bombs won’t bubble. So you really want to get the proportions right.
DIY Bubble Bath Bomb: Summer Swim
The Summer Swim bath bomb is a bath bomb recipe I created that uses SLSa. Note the proportions in the ingredients below:
- 1 pack expandable sea toys
- 2 cups baking soda
- 1 cup Epsom salt
- 1 cup cornstarch
- 2 tsp powdered mica colorant – deep blue
- 1 cup citric acid
- 1/2 cup SLSA
- 2 tsp biodegradable glitter
- 20 drops Ylang-Ylang essential oil
- 2 Tbsp sweet almond oil
- 1 Tbsp cold water
- witch hazel in spray bottle
But in any case, when I make bubble bath bombs, I like the bubbles to mean something. That’s why I incorporate bubbles with the theme of the bath bomb. My Summer Swim bath bomb, for example, is inspired by my childhood near the beach in a New England seaside town. All those evening summer swims!
I tried to replicate the feeling I had standing on the shore, watching a wave break, and the sea bubble up around my ankles. This bath bomb bubbles and glitters like a sparkling ocean.
If you’d like to make this bath bomb, you can get the full directions here.
How to Safely Essential Oils
If you’re pregnant, breastfeeding or have skin irritation or a chronic illness, you probably won’t want to use bath products with essential oils. Read more about how to safely use essential oils in the tub, including dilution with carrier oils and patch testing.
Don’t Forget the Air
There’s one last important component of any good bubble and that’s air.
In general, the greater the force of the air entering the soap-water-soap molecules, the larger the bubbles. One way to add air pressure to your bubble bath bombs is to throw them into the water just beneath the running tub spout. The pressure of the running water will force air into the molecules of your bubble bath bombs.
Another great way to add more air and enhance the bubble-ocity is to make your bath bombs spin! And what could be more exciting than a spinning, bubbling, frothing bath bomb?
The trick for making bubble bath bombs spin, and therefore more bubbly, is to plant embeds inside them.
Embeds for Even More Bubbly Bath Bombs
Embeds are like little bath bombs inside your bath bombs, but the consistency is much harder than that of a bath bomb. Embeds are also super easy to make. Here is a quick recipe. And if you have the ingredients for a bath bomb, you won’t need anything else except a mold. You can use an ice cube tray or a mini-silicone mold.
The secret to making your embeds spin successfully—as they whip air into the bath bombs—is to place the embeds off-center. Let me say that again: Do not put them in the dead center your bath bombs. Instead, put them about a third deep into the mixture and place them off to the side a bit.
The off-center placement causes disequilibrium that will keep your bubble bath bombs moving as the embed basically explodes inside it. Trust me, this is the secret to the bubbliest of all bubble bath bombs!
How to Create Your Own Bubble Bath Bombs
What could be more fun than creating your own bubble bath bomb recipe! Here are some guidelines to get you started:
- Start with a basic bath bomb recipe.
- Think of a theme related to bubbles, whether it’s mermaids, a teapot, or bubble gum.
- Add SLSa in proportion to the other ingredients.
- Consider what else you can add to enhance the theme, whether it’s pink colorant for a bubble gum themed bubble bath bomb, or pink and green glitter for a mermaid-themed bubble bath bomb.
- For maximum fizz, spin and bubbles, make an embed and place it off-center between the two halves of your bath bomb mold.
Your bubble bath bombs should last 6-12 months if stored properly. Read more about expiration dates for bath bombs and how to store them.
Homemade Bubble Bath Bombs
If you’ve read this post, you’re thinking about making bubble bath bombs. Now is the time I sincerely urge you to do it! Why? Because life is tough, but making bubble bath bombs is a tonic to cure what ails you. The process will require you to summon the imaginative and scientific parts of your brain, before you can toss your creation in the tub and experience giggly, bubbly joy!
And by the way, if your philosophy is “The more bubbles the better!”, check out my post The Secret to a More Bubbly Bubble Bath.