Bath bombs are an every year “must make” for me as I have several lovely people (mostly my mom) on my giftee list that adore bath bombs. Once I settled on this year’s themes, I knew the bath bombs would have to be Frosted Cranberry themed because they could actually be made to look like frosted cranberries! Bring on the spherical mould and frosty micas!

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I opted to hand-mould these bath bombs, which is something I haven’t done since early 2019 as my Bath Bomb Press has taken over all pressing duties due to its general awesomeness. As I’ve modified the way I make bath bombs quite a lot since then (more details on that here), I decided it was time to bop back over to hand-moulding for an updated demo (plus I don’t have a spherical Bath Bomb Press mould the same size as my hand sphere mould, and that’s the size I wanted to make 😝).

These bath bombs get their cranberry colour from a red water-soluble dye. I tried including the dye with the baking soda and pre-dissolved it in the witch hazel, and that small change makes a big difference! The pre-dissolved bath bombs are much more vibrant than the bath bombs where the dye was mixed into the baking soda. They both colour your bath water the same amount, with the pre-dissolved ones giving a much more uniform colour burst while the paler bath bombs will spit out little extra-red hot spots as they fizz away.

The “frosted” look comes from a dusting of frosty silver-white mica and a sprinkling of biodegradable glitter. I used a sieve to tap the mica over the bath bombs, just as I’d dust a cake with icing sugar.

Toss one of these beauties into your bath and you’ll be rewarded with lots of fizzing, cranberry-juice-coloured bathwater, and silky, rich bath water. Enjoy!

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Relevant links & further reading

• Baking Soda in the Humblebee & Me Encyclopedia
• Citric Acid in the Humblebee & Me Encyclopedia
• Polysorbate 80 in the Humblebee & Me Encyclopedia
• Cranberry Seed Oil in the Humblebee & Me Encyclopedia
• More bath bombs:
  • Ice Palace Bath Bombs
  • Argan Rose Valentine Bath Bombs
  • Winter Solstice Bath Bombs

Frosted Cranberry Bath Bombs

530g | 53% baking soda (USA / Canada)
95.5g | 9.55% Epsom salt (USA / Canada)

5.4g | 0.54% witch hazel distillate (USA / Canada)
17.6g | 1.76% Polysorbate 80 (USA / Canada)
26g | 2.6% cranberry seed oil
5g | 0.5% white cranberry fragrance oil
0.5g | 0.05% acid red 18 dye

270g | 27% citric acid (USA / Canada)
50g | 5% Cream of Tartar (USA / Canada)

To decorate:

• Silver-white mica
• Silvery biodegradable glitter

To hand mould: 70% isopropyl alcohol in a mister bottle

Weigh the dye, witch hazel, Polysorbate 80, cranberry oil, and fragrance oil into a small dish or beaker.

Weigh the baking soda and Epsom salts into a large bowl. Stir to combine, and then add the witch hazel mixture. Put on a pair of disposable nitrile or latex gloves and blend the mixture thoroughly.

Last up, weigh in the citric acid and Cream of Tartar, and blend that into the mixture as well. When you’re done you should have a clumpy mixture that holds together well when squeezed firmly.

Now you’re ready to mould! You can press these bath bombs with a press (I love my Bath Bomb Press!) or hand-mould them. I opted to hand-mould this batch using a spherical mould; please watch the video for full instructions! If the bath bombs start to become finicky as you work, that’s likely because the mix is starting to dry out—mist in some 70% isopropyl alcohol until they become workable again.

Once the bath bombs have been moulded I left them to dry overnight before decorating them.

To decorate: Use a sieve to dust the tops of the bath bombs with silver-white mica, and then sprinkle with some biodegradable glitter. That’s it!

To use the bath bombs, just drop one or two into a hot bath. Enjoy!

Shelf Life & Storage

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.

Substitutions

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

• As I’ve provided this recipe 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 recipe will make 1000g (1kg!) of bath bombs.
• 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.
• Don’t substitute the baking soda or citric acid.
• You could try a different salt in place of Epsom salts.
• You can try replacing the Cream of Tartar with more citric acid, but the Cream of Tartar makes the bath bombs much harder and easier to mould.
• Give this a read for Polysorbate 80 alternatives.
• You can substitute another lightweight oil like sweet almond, grapeseed, or sunflower seed oil instead of cranberry seed oil.
• The fragrance is up to you. You could use a bath-safe essential oil instead, or any fragrance oil you like (within IFRA guidelines).
• To colour the bath bombs: stick with water-soluble dyes as they’re super potent at low concentrations and will dye your bath water without leaving a ring in the tub.
• The “frosted” topping is optional (but pretty!).