It’s been entirely too long since I’ve made bath bombs, and with the return of cooler temperatures I couldn’t think of anything more appropriate than a lovely batch of glitter-sprinkled Pumpkin Spice Bath Bombs. A chilly night, a big mug of tea, a bit of tub-side Netflix, and a foaming, fizzing, fragrant bath sounds like heaven. In addition to the usual fizz of a bath bomb I also decided to add some foamy, lathery goodness to these bad boys for some extra bath time fun—whee!
With this batch of bath bombs I decided to drop the oil portion and see how that worked out. I usually include a bit of liquid oil and liquid solubilizer like Polysorbate 80 or Olivem300 to emulsify that oil into the bath water, but this time I thought I’d go the “basically fizzy bath salts” route and see what I thought. The first thing I noticed was how much faster it made the bombs to make; removing the oil mostly eliminated the step of blending all the ingredients into a portion of the bath bombs and then blending that into the rest of the powder. I still had to do that with the essential oils and some baking soda, but it was a significantly smaller amount of liquid so I could do it all in my coffee grinder without pulling out my food processor. I know it doesn’t sound like a huge difference, but I definitely noticed!
I also incorporated some Sodium Lauryl Sulfoacetate (SLSa), a powdered anionic surfactant. It’s gentle and high foaming, as well as being readily water soluble, making it an awesome choice for a single-surfactant addition to a bath bomb. If you don’t have it Sodium Coco Sulfate or Sodium Cocoyl Isethionate will both also work, but they will produce different lather (SCI in particular won’t be quite as lofty). If you don’t want to include a surfactant you can simply replace it with more Epsom salts.
For all of the powdery bits you’ll definitely want to wear a dust mask—citric acids or a powdered surfactant in the wind pipes does not feel good! Now, the only tricky-ish part of bath bombs is adding the liquid; you want just enough that you can press the mixture together and it’ll fuse into a solid bath bomb, but not so much that the liquid triggers the reaction, leading you to return to your should-be-dry-by-now bath bombs and finding sad, swollen, misshapen lumps in their place.
You’ll want to use a mister bottle to distribute the liquid over as wide an area as possible, and a whisk to keep it really dispersed. Squeeze handfuls of the mixture as you work and once it holds together well-ish, you’re good to go. The core of your handful of mix should be fairly sturdy, but the edges can still be a bit crumbly. You can do a test bath bomb if you’re not quite sure—if it holds together well once you tap it out, you’re good to go! If it slumps like a dry sand castle, pop that back into the bowl and add a few more spritzes of liquid.
The glittery topping is pretty, but optional. You could also use a different colour, or a mica if that’s what you’ve got. I intentionally left out ground versions of the spices so you don’t have to wipe down your tub of spicy residue post-soak, bit if you really want to add a teaspoon of pumpkin spice you certainly can. Mmmm, pumpkin spice!
Pumpkin Spice Bath Bombs
2020 update: Given the irritation potential for this essential oil blend, I’d recommend using a pumpkin spice fragrance oil rather than the essential oil blend. Please refer to supplier documentation for maximum usage rates for the particular fragrance oil you’re using when used in in-bath products; 0.1–0.2% should be more than enough to adequately scent the product.
Gold glitter, as needed (optional)
Begin by scooping a few tablespoons of baking soda into your DIY-only coffee grinder. Scatter the essential oils over top, gently shake the coffee grinder a wee bit to sift some baking soda over top of the drops of liquid essential oils, and then blend to combine.
Put on your dust mask and measure the rest of the powdered ingredients into a large bowl and whisk together, using the back of a spoon to break up any clumps. Whisk in the baking soda/essential oil mixture until the blend is uniform.
Now it’s time to add just enough liquid to get the mixture to hold together in a mold. Not too much, though, or it will react in the bowl/mold, not in your bath. That’s why we’re using a mister (it’ll spread the moisture better) and witch hazel (the reaction isn’t as vigorous when you use witch hazel, plus the bath bombs dry faster).
So, spread your mixture out in your bowl so you have as much surface area as possible, and spritz. Then quickly stir/whisk thoroughly. Repeat until you can grab a clump of the mixture and it will just hold together after a firm squeeze.
Once the mixture will hold together, it’s time to mold it! I sprinkled a wee bit of gold glitter into the bottom of a quarter-cup measuring cup and then crammed as much tightly-packed bath bomb mix on top of that. Tap that out onto a sheet of wax paper. Let dry overnight, turning once.
To use, drop in a hot bath and enjoy! This recipe will make about ten quarter-cup bath bombs.
Because these bath bombs don’t contain any water once they dry, they do not require a broad-spectrum preservative (broad spectrum preservatives ward off microbial growth, and microbes require water to live—no water, no microbes!). Be sure to keep them dry to ensure they last as long as possible—don’t let any water get into the container/bag you store them in and they should easily last a year.