These Winter Wonderland Shimmery Foaming Bath Salts are pretty darn fun, and make for a fabulous gift. Much like a bath bomb, they fizz and foam and transform your bath water into silky loveliness—but they’re much easier to make. They also smell great and add a bit of biodegradable holiday sparkle to your soak. Basically, if you’ve ever wanted to take a bath in the liquid from a snow globe, these bath salts just might be for you 😅

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When making bath salts, the biggest formulation challenge is ensuring they remain free-flowing. My earliest bath salt attempts were lovely… for about a week. After that they’d seize up into a solid brick in whatever container they were in, making them pretty darn impossibly to use. Boo. Thankfully, we’ve got a couple ingredients in our formulation tool kits to keep our bath salts from turning into bath cannon balls.

In the past I’ve mostly used Dendritic Salt, but this time I decided to use NATRASORB® BATH. Natrasorb is a modified tapioca starch. It is water soluble and can absorb a lot of oils and oily things like fragrances, essential oils, and oil-soluble solubilizers without wetting out and getting clumpy. It’s also ultra light and fluffy; the 15g I used in this formulation was approximately a cup of powder!

To use NATRASORB® BATH, simply blend the fragrance oil and solubilizer (this allows the fragrance oil to mix into the bath water) into it until uniform. Then you’ll add the rest of the dry ingredients, stir, and spread the mixture out to dry for a couple days before packaging. And that’s it!

The rest of the dry ingredients in these bath salts can be sorted into four categories/jobs.

The first is the fizz! A blend of basic baking soda and acidic citric acid react once the bath salts are added to water, creating a really fun fizzing effect—just like a bath bomb.

The second is suds; some natural Sodium Lauryl Sulfoacetate (SLSa) means these bath salts are also part bubble bath! Make sure you are wearing your respirator when working with this ingredient. I’ve listed some alternatives in the Substitutions list below if needed.

The third is the salty stuff—these are “bath salts”, after all! I’ve chosen a blend of Epsom salts (great for sore muscles) and inexpensive fine sea salt. You can play with the salt blend if you want to, just be sure to stick to relatively fine grained salts that will dissolve easily. I learned the uncomfortable way that larger chunks of salt (like super pretty medium-sized pink Himalayan salt) don’t dissolve very well, so it ends up feeling like you’re sitting on a bunch of gravel in the tub 😬

And the fourth is the shimmer! Just half a percent of a wintery biodegradable glitter gives these bath salts—and our bath water—a gorgeous, slow globe sort of effect. Please be certain your glitter is biodegradable; we don’t want to be sending microplastics down the drain.

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Relevant links & further reading

• NATRASORB® BATH in the Humblebee & Me Encyclopedia
• Polysorbate 80 in the Humblebee & Me Encyclopedia
• Baking Soda in the Humblebee & Me Encyclopedia
• Citric Acid in the Humblebee & Me Encyclopedia
• Sodium Lauryl Sulfoacetate (SLSa) in the Humblebee & Me Encyclopedia
• How long will ______ last? What is its shelf life? in the Humblebee & Me FAQ
• Other bath salts formulas:
  • French Spa Bath Salts
  • Popping Cocoa Coconut Bath Salts
  • Lavender Oat Foaming Bath Salts

Winter Wonderland Shimmery Foaming Bath Salts

15g | 15% NATRASORB® BATH (USA / Canada / UK / NZ)
1g | 1% Polysorbate 80 (USA / Canada)
0.5g | 0.5% wintery bath-safe fragrance oil or essential oil

20g | 20% baking soda (USA / Canada)
10g | 10% citric acid (USA / Canada)
10g | 10% Sodium Lauryl Sulfoacetate (SLSa) (USA / Canada)
22.5g | 22.5% Epsom salt (USA / Canada)
20.5g | 20.5% fine sea salt (USA / Canada)
0.5g | 0.5% silver-white biodegradable glitter

Weigh the NATRASORB® BATH, fragrance, and polysorbate 80 into a bowl. Massage everything together with gloved hands until the mixture is uniform.

Put on your dust mask/respirator.

Weigh out the baking soda, citric acid, Sodium Lauryl Sulfoacetate (SLSa), Epsom salts, sea salt, and glitter. Add them to the NATRASORB® BATH mixture and blend with gloved hands until uniform.

Spread the mixture out on a cookie sheet and leave it to dry for two to three days before packaging.

Package in some sort of air-tight container. I filled one 100mL (3.3fl oz) screw-top test tube and three 40mL (1.35 fl oz) test tubes with this 100g (3.5oz) batch.

To use, add the desired amount to a bath as it is running; 20g is a pretty decent amount for a bath. Enjoy the bubbles and the lovely silky water!

Shelf Life & Storage

Because this product does not contain any water, it does not require a broad-spectrum preservative (broad spectrum preservatives ward off microbial growth, and microbes require water to live—no water, no microbes!). Kept reasonably cool and dry, it should last at least a year or two before any of the oils go rancid. If you notice it starts to smell like old nuts or crayons, that’s a sign that the oils have begun to oxidize; chuck it out and make a fresh batch if that happens.

Substitutions

As always, be aware that making substitutions will change the final product. While these swaps won’t break the formulation, you will get a different final product than I did.

• As I’ve provided this formulation in percentages as well as grams you can easily calculate it to any size using a simple spreadsheet as I’ve explained in this post. As written in grams, this formulation will make 100g; this created approximately 220mL of bath salts.
• To learn more about the ingredients used in this formulation, including why they’re included and what you can substitute them with, please visit the Humblebee & Me Encyclopedia. It doesn’t have everything in it yet, but there’s lots of good information there! If I have not given a specific substitution suggestion in this list please look up the ingredient in the encyclopedia before asking.
• You can use 10% Dendritic Salt instead of NATRASORB® BATH (replace the missing 5% with more sea salt). This will impact the feel of the bath water (it won’t be as silky) and will reduce the total volume of the bath salts.
• Polysorbate 20 should work well instead of polysorbate 80. You could also try a different oil-soluble solubilizer.
• If you’d like to incorporate an essential oil, please read this.
• If you’d like to incorporate a different essential oil, please read this.
• I don’t recommend substituting the baking soda or citric acid.
• You could try Sodium Cocoyl Isethionate (SCI) or a different solid anionic surfactant instead of Sodium Lauryl Sulfoacetate (SLSa); just be sure it is finely powdered so it dissolves easily.
• You can play with the salt blend, just be sure to stick to relatively fine grained salts that will dissolve easily.
• The glitter is optional; replace it with more sea salt if you don’t want to use it.
• As written, this formulation is 98.5% natural; the only not-natural ingredients are the fragrance oil (easily swapped for a bath safe essential oil or natural fragrance oil) and the polysorbate 80 (you’ll need a natural anhydrous/water-free solubilizer; Poly Suga®Mulse D9 [INCI: Sorbitan Oleate Decylglucoside Crosspolymer] is a good option).