This formulation is a really fun and interesting one; it’s a solid, self-preserving body wash that I’m calling Birthday Suit Solid Body Wash. You can customize the colour and the scent, and play with different moulds for all kinds of fun! It’s also easy to make—mix, melt, pour, and you’re done. I had a lot of fun developing this formulation and I hope you have fun making it 😄
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The inspiration for this formulation was a discontinued LUSH product; their Naked Shower Gel. The ingredients list showed the base of the bar was a blend of propylene glycol and sodium stearate; this is the same base many commercial stick deodorants use. After that, the bars were mostly comprised of a blend of different surfactants, colourants, and fragrance oil.
As a rather interesting aside—this is a very similar structure to not-actually-soap melt & pour bases, like this or this. If you take a look at the ingredients you’ll recognize propylene glycol, sodium stearate, and a blend of surfactants to create a solid base that looks like soap. So, with that in mind, you can sort of think of this formulation as your own from-scratch DIY not-soap melt & pour 😂
I started my formulating work by looking at a selection of sample deodorant formulations using a sodium stearate/propylene glycol base, like the one linked on this product page. With a general idea of sodium stearate/propylene glycol ratios, I had my base to add surfactant, fragrance, and colour to. Draft number one came together beautifully, but once left on a drying rack for a day or two the bar got all kinds of slimy and drippy—the bars didn’t contain enough sodium stearate to stay fully solid. So, I worked on increasing the sodium stearate content to create something that was sturdy, solid, and lathers up beautifully.
I used Sodium Coco Sulfate (SCS) as the primary surfactant, just like LUSH did, complimenting it with amphoteric Cocamidopropyl Betaine for a milder overall product. This blend creates oodles of rich, luscious bubbles!
I used a microplane zester to shred up the bars to test the pH.
As I worked on this formulation I played with tons of different colour and scent combinations and used lots of different moulds. Because we pour this product while it’s still quite a thin liquid, and then it sets up very firm, it’s a great opportunity to break out some of your more detailed moulds. The pretty-photo bars use a blend of red and orange dyes to create a peachy colour to match the Peach Prosecco fragrance oil I used, and then I filled three of the bumblebee cavities in my silicone honeycomb mold (USA / Canada).
Let’s talk pH a bit. This bar is pretty basic, and it has to be. This bar has a pH similar to that of soap; approximately 9.45. And that’s for a good reason—sodium stearate, our hardening agent, is saponified stearic acid. It’s soap, and soap has to be basic. As you lower the pH of this bar, it gets softer. At pH 8.69 I could dent the bar with a thumb and some effort; pH 8.38 and it dented when I removed it from the mould; pH 7.52 and it was a sticky, soft paste that I accidentally smashed/squished into multiple soggy lumps (I wouldn’t call it “breaking” because it was about as soft as a baked potato and I can’t imagine “breaking” a baked potato 😂). If you’d like to learn more and see the different bars and their varying levels of squishiness, I made an entire video about my experiments as an exclusive for my $10 and up patrons.
Want to watch this project instead of reading it?
This is a really fun formulation to play with and I had a lot of fun creating different versions and experimenting. I don’t use this bar for my face due to the high pH, but I like it as a body wash. Enjoy!
Relevant links & further reading
- Sodium Stearate in the Humblebee & Me Encyclopedia
- Propanediol 1,3 in the Humblebee & Me Encyclopedia
- Preserving Botanical Formulations Naturally – Part 1 from Botanical Formulations
- Preserving Botanical Formulations Naturally – Part 2 from Botanical Formulations
- How can I incorporate X ingredient into a formulation?
- How much essential oil can I add to this recipe?
- Humectants from Colin’s Beauty Pages
- Propylene Glycol and Polypropylene Glycols from Cosmetics Info
Birthday Suit Solid Body Wash
Heated phase
5g | 10% Cocamidopropyl Betaine (USA / Canada)
0.005g | 0.01% water-soluble dye
22.145g | 44.29% Propanediol 1,3 (USA / Canada) or propylene glycol
0.2g | 0.4% citric acid (USA / Canada)12.5g | 25% Sodium Coco Sulfate (SCS) (USA / Canada)
10g | 20% sodium stearate (USA / Canada)Cool down phase
0.15g | 0.3% fragrance oil or essential oil of choicePreheat your oven to 225°F (~110°C).
Weigh the first four heated phase ingredients into a small heat-resistant glass measuring cup or beaker. Stir to combine and bloom the dye. Add the last two ingredients (you’ll need to wear a dust mask when the surfactant is dry) and stir until everything is well distributed. Place the measuring cup or beaker on a cookie sheet, and put everything into the oven. Heat through until everything has melted.
Once you have a clear liquid, remove it from the oven. Quickly weigh in the cool down phase (take steps to protect your scale—watch the video!), stir to combine, and pour the mixture into your mould. Leave it to solidify.
When the bar has started to pull away from the edge of the mould, gently pop it out, and you’re done. Leave the bars for a day or two before using—use as you’d use a bar of soap. Enjoy!
Shelf Life & Storage
Thanks to the high pH and high humectant content, this solid bodywash is self-preserving. I left some of these bars in my shower for over 18 months and they never showed any signs of spoilage.
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 50g.
- 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.
- If you’d like to learn more about the surfactants used and compare them to ones you might already have so you can make substitutions, check out this page and read this FAQ. I think there’s a lot of room to play with different surfactants with this general formulation idea, but if you switch to a liquid one there’s a good chance you’ll have to re-develop the formulation.
- If you’d like to incorporate an essential oil, please read this.
- I don’t recommend mica instead of a water-soluble dye; you need to pour this while it’s still really thin, and mica will likely settle out as it sets.
- You can use propanediol 1,3 or propylene glycol. I have not tested any other alternatives and cannot recommend any.
- I don’t have any suggestions for substituting out the sodium stearate. If you don’t have it, this formulation probably isn’t for you.
- You cannot make this bar acidic. The citric acid in this formulation lowers the pH a wee bit; I found any more acid started to make the bar soft. If acidity is important to you, this is not a thing you should make.
Gifting Disclosure
The water-soluble dyes were gifted by YellowBee.
This is really interesting! Do you know if it can be remelted like melt and pour soap base?
It probably can, though I haven’t experimented with that myself 🙂 Let me know if you try it!
Hello queen bee!
I was curious to know that can I substitute scs with sci(babyfoam)?
Thanks!
I’ll refer you to the third point in the substitutions list 🙂 That’s all I can really say beyond “try it!” 🙂 Happy making!
Hello, I tried the recipe and I wanted to double it.; which I did. Looking for guidance for when I want to make these in a larger amount again.
It would not completely liquefy in the oven, so, I then moved the recipe to a water bath and had to bring the water bath level to the height of the recipe level in my Pyrex container , because the ingredients would start to go solid on the surface. With that being said, I still had a terrible time getting everything to melt to a liquid state. Should I try a different way to melt and what do you suggest? I did get most of the recipe into a liquid state after 45 minutes of stirring and heating at a high boil; but I still had clumping issues. They molded ok except for the clumps here and there. The recipe works as far as the solid bar.
Lots of bubbles and very silky. Its just the melting part a larger batch. What do think?
Sincerely,
Lisa
Can this formula be customized with any cosmetic additives like panthenol or allentoin? Is that possible with an anhydrous product like this? Very awesome btw I ordered what I needed to make this like as soon as I saw your post…cant wait! Thanks Queen Bee!!
Probably 🙂 I’d take your customizing cues from what is recommended for M&P soaps with similar ingredient lists, and remember that the pH has to be high, so actives that require a lower pH wouldn’t be well suited 🙂 Happy making!
I’ve tried this recipe at 225 deg F and 250 deg F but never get full melting. I get a thin, clear bottom layer and a thick white top layer that neither fully melts or mixes with the bottom layer when hot. I also put one batch in the microwave to try to force melting but it separated. Any suggestions as to what I could be doing wrong? Many thanks!
It is normal to have a wee bit of white foamy-looking on the surface. Did you change anything? Your description sounds like you’ve got a lot more white than I did. That said, if you feel like it’s not changing any further, just pull it out, whisk in the cool down phase, and pour it to see what happens. There’s a decent chance it’ll be ok.
Hi Marie! Couldn’t wait to try this out…never made soap before, but this bar idea really appealed to me. Sooooooo… I picked up the couple things I didn’t already have. Mixed it all together, but it’s been in the over for almost an hour now…how long should it take to melt???
How long will depend on oven temp and batch size, but an hour seems awfully long. It is normal to have a wee bit of white foamy-looking on the surface. If you feel like it’s not changing any further, just pull it out, whisk in the cool down phase, and pour it. It’ll probably be fine 🙂
Hallo Marie.. i’ve try this solid soap..but why its surface always wet… oily ..we must curing?
It sounds like you live somewhere very hot & humid? If so, you’ll likely want to wrap the bars in something air-tight shortly after making them.
Hi Marie!
A very fun recipe indeed. I put pumice stone in it, so that a kind of scrub was created, to get hands that worked hard, nice and tidy again.
Thank you for sharing! It’s great to know that adding exfoliants can work well 🙂 Thanks for DIYing with me, and happy making!
Hi. Did you use powder or noodle sodium coco sulfate?
Thanks!
It doesn’t matter what you use, but I used noodles (they are linked in the formulation). Thanks for DIYing with me, and happy making 🙂
I am trying to learn to formulate, but find it can be so confusing. In your Encyclopedia, and other places I’ve read SCS can be used at 1-15% but you have it here at 25% and I have another formulation that has it at 40%. Can you help me understand how the usage rate is 1-15% but it’s used at a higher rate in formulations? Thank you!
Just wondering why you’re adding .4% citric acid to this? Doesn’t that lower the PH of the entire formulation to a range where the sodium lactate may not remain sodium lactate? I made these to the letter and got white spots all over the bars although they did perform gorgeously. I’m going to try and remake again without the citric and see what happens. There’s a post on Facebook about it.
Hi Denise! I assume you mean sodium stearate, not sodium lactate? There’s no sodium lactate in this formulation. It lowers the pH a little but, but it’s definitely still high enough for the vast majority of the sodium stearate to be itself. It’s kind of like introducing a small superfat percentage. I shared some experiments with my patrons where I added varying amounts of acid and you end up getting smooshy paste well before the pH hit 7, where all the sodium stearate would be gone. Dropping the citric acid will result in a slightly harder bar with a slightly higher pH.
Since this is basically melt and pour soap, I’d try search queries around “why my M&P soap has white spots”. Here are some articles I found:
https://lovinsoap.com/2017/01/white-spots-in-soap/
https://www.soapmakingforum.com/threads/white-spots-in-melt-and-pour-glycerine-soap.84037/
https://thenerdyfarmwife.com/troubleshooting-cold-process-soap-problems/#section23
Happy making!