Today we’re squishin’ and mixin’ up a batch of pretty pink sulphate-free shampoo bars, featuring Australian pink clay and a blend of gentle surfactants. These beautiful bars kick out all kinds of gorgeous, creamy lather, and leave your hair wonderfully clean. They also take on a really cool mosaic-like appearance as you use them thanks to the contrast between the lumpy white Sodium Cocoyl Isethionate (SCI) and the deep pink clay. Neat!
Want to watch this project instead of reading it?
These bars were borne out of some experiments I did after sharing my Chocolate Rhassoul Shampoo Bars last year. There were lots of questions about using different clays and surfactants, so I got to mixing, squishing, and pressing to see what happened. If you compare the percentages in this formulation you’ll notice they’re extremely comparable to the chocolate bars, just with (some) different ingredients.
Rather than noodles, I chose powdered surfactants. The Sodium Lauryl Sulfoacetate (SLSa) I used is an extremely fine, floaty powder, while the Sodium Cocoyl Isethionate (SCI) is a chunky, rough sort of powder that I got from Windy Point a couple of years ago (they’ve since stopped selling that format). The bag I’ve got has anything from ultra-fine dust up to uneven chunks ~5–7mm across. That chunkiness is what gives these bars their “mosaic” appearance—the uneven white bits of surfactant contrast beautifully against the deep pink background the Australian pink clay creates. If you have Sodium Cocoyl Isethionate (SCI) noodles that’ll work, too, though the end look will obviously be a bit different. If your SCI is finely powdered that can also work, but you may need to drop the Sodium Cocoyl Isethionate (SCI) by a few percentage points and add a bit more Cocamidopropyl Betaine to account for the increased absorption powers of the higher surface area format.
I chose Australian pink clay for the clay part for a couple of reasons. 1) I thought it would look pretty; 2) it’s quite different from rhassoul in that it creates creamy/pasty mixtures rather than more sandy ones; 3) I have a lot of it and haven’t found many places to use it. The texture change from rhassoul combined with the powdered surfactants (instead of the needles in the rhassoul bar) made a big difference in the consistency of the final mixture—it’s far more dough-like than the much more crumbly rhassoul bars, making it much more hand-moulding friendly if you don’t have a press. I’ve since played with quite a few different clays in shampoo bars and I am really loving the dough-like quality the softer clays lend to a shampoo bar mixture—stay tuned for more!
While you certainly don’t need a press to make these shampoo bars you will need a tight-fitting dust mask (not one of those disposable cardboard ones!) and a pair of nitrile gloves for mixing everything together. I’ve been using this dust mask for going on two years now and I really like it; it’s comfortable and fits really well so I don’t end up gagging in sneaky surfactant dust as I work. The press I’m using is The Bath Bomb Press with the 1.75″ square cube mould, and I’ve been very impressed with how it performs.
After pressing you’ll need to leave these bars to dry before use. They dry out at roughly the same rate as the Chocolate Rhassoul Shampoo Bars. Both bars contain about 3.6% water when made due to the water content of Cocamidopropyl Betaine (~60% water). The Chocolate Rhassoul Shampoo Bars lost about 1.2% of their weight in 10 days while these bars lose about 1.1% of their weight in 10 days—and given my sample sizes, that’s likely within the margin of error. Just like the Chocolate Rhassoul Bars, I’d leave these pink bars to dry for 7–10 days to get about 1% loss, and I’d consider 48 hours the minimum amount of drying time.
Want to watch this project instead of reading it?
Pink Clay Mosaic Shampoo Bars
Prepare a water bath by bringing about 3cm/1″ of water to a bare simmer over low to medium-low heat in a small saucepan.
While the heated phase melts, put on your dust mask and weigh the dry surfactants into a bowl. Weigh out the cool-down phase and set it aside.
Once the heated phase has melted, pour it into the dry surfactants. Put on a pair of nitrile gloves and blend thoroughly with your hands. Once the mixture is uniform, add the cool-down phase and blend that in as well. You’ll be left with a stiff, easily-mouldable paste.
Now it’s time to press the bars! I used the cube mold, pressing roughly 75g of the shampoo bar mixture into each bar. I highly recommend lining the top and bottom of the mould with some cut-to-size pieces of parchment paper to prevent sticking & make unmoulding nice and easy. I set the regulated pressure on my compressor to 55psi. Please watch the video to see this in action. If you don’t have a press you could try hand-pressing the mixture into a firm mold (I don’t recommend silicone as the sides tend to bow out if you really try to compress a mixture in one, and this bar needs some serious squishing). I’ve also heard good things about moon cake presses!
Carefully un-mold the bars and leave them to dry for at least 48 hours, but preferably 7–10 days, before using.
To use, massage the bar into wet hair (or a wet loofah, for body washing) to work up a rich lather. From there on out it’s just like using any other shampoo or body wash. Enjoy!
When made as written, the pH of these shampoo bars comes out to ~5, which is great.
Because these shampoo bars will regularly come into contact with water, I recommend including a broad-spectrum preservative to ward off microbial growth.
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 150g (roughly two 75g [2.65oz] bars, depending on how much mix is lost to the bowl).
- To learn more about the ingredients used in this recipe, 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.
- Cocoa butter will work instead of kokum butter; I recommend using refined.
- You could try cetearyl alcohol or cetyl alcohol instead of stearic acid.
- For the clay: I’d recommend choosing a different soft, creamy clay, like other Australian clays, a French clay, or kaolin. I do not recommend bentonite or rhassoul. If you want a bar using rhassoul, check out this one!
- To get the same visual effect I don’t recommend swapping out the Sodium Cocoyl Isethionate (SCI) or Sodium Lauryl Sulfoacetate (SLSa) (including the formats, like choosing a finely powdered version instead of the lumpy powder):
- I know the precise Sodium Cocoyl Isethionate (SCI) I used isn’t readily available anymore, so if you can’t find a chunky powdered format I think the needles would be my next choice, though this will obviously change the end look of the bars.
- You could try a different finely powdered anionic surfactant in place of Sodium Lauryl Sulfoacetate (SLSa)
- If you change up the surfactants be sure to check and possibly adjust the pH of the final bars
- You can use a different fragrance or essential oil. Be sure to watch maximum usage levels.
- If you’re like to use a different preservative, please review this page.
- 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.