Today we’re kneading up a really simple shampoo bar that kicks out oodles of silky, luscious lather. You’ll only need seven ingredients, there’s no heat required, and you can whip up a batch in less than twenty minutes!

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The basic formulation structure

This shampoo bar comes together a lot like pasta dough does; you’ll be working just enough wet stuff into a bunch of smooth, powdery dry stuff to create a workable dough. You’ll then shape that dough and leave it to try. However, instead of flour and eggs becoming long noodly shapes, we’ll be using powdered and liquid surfactants, oil, and other cosmetic ingredients to create bar shapes.

The balance between the wet and the dry ingredients is essential to creating a workable dough; if it’s too dry it’ll be crumbly, but if it’s too wet it’ll be sticky and crack as it dries out (ages). This balance will always be more dry than wet. This formulation is 74% dry to 26% wet, but that ratio can change quite a lot depending on what the dry ingredients are. Different starches, surfactants, and formats of surfactants (fine powders vs. chunky powders vs. tiny needles) can all change the required ratios.

What gives this shampoo bar its cleansing power?

Our sudsy, bubbly, hair-cleansing goodness comes from a blend of two surfactants.

The primary surfactant is Sodium Lauryl Sulfoacetate, also known as SLSa. This is a gentle ECO-CERT surfactant. It is anionic, creates gorgeous silky lather, and is generally pretty easy to get around the world. It is also solid, taking the form of a fine, lightweight, silky white powder. Third part is really important as the solid-ness of the star surfactant is a major part of what creates a solid shampoo bar. I did work on some versions of this formulation that used Sodium Cocoyl Isethionate (SCI) instead, but found I preferred the Sodium Lauryl Sulfoacetate (SLSa) dough.

Our second surfactant is amphoteric Cocamidopropyl Betaine. This liquid surfactant helps wet out the dry stuff in this formulation to create a dough; it also boosts flash foam and makes the shampoo bar milder.

What else is in the formulation?

Some oil—I used Fractionated coconut oil but you could easily swap that out—re-fats the bar so the shampoo doesn’t dry out your hair.

Optiphen™ Plus preserves the bars.

Can I use a different preservative than the one you’ve used?

Some fine, silky rice flour (which feels far more like cornstarch or arrowroot starch than wheat flour) is a readily accessible, solid-but-not-surfactant ingredient that contributes to the solidity of the bar without making it stronger/more cleansing. I prefer bulking the bar with powders like starches and clays that can’t melt; I’ve found using lots of fatty alcohols for this job makes bars that get quite gooey as they live out their life in the shower (especially if you live somewhere hot & humid).

What’s the best way to shape this shampoo bar?

I’ve found this dough works best when smooshed/mashed into a hard-sided mould. I used a cute daisy vacuum mould from Breaking the Mold YYC in the video, but something as basic as a measuring cup could work, too.

These bars can be hand shaped, just take care to smooth out the cracks that will form as the dough is manipulated (having ‘walls’ in the form of a mould prevents these cracks from forming). I find smaller bars are easier to hand shape than larger ones.

And, if you have a press (manual or otherwise), you can absolutely press these bars!

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What equipment will I need to make these bars?

You’ll need:

  • A digital scale that’s accurate to at least 0.1g: for weighing the ingredients.
  • A well-fitting respirator/dust mask: essential to prevent gagging on the powdered surfactants, which will make a beeline for any exposed airway regardless of how careful you are.
  • A pair of gloves (nitrile/latex/rubber): So you can mix everything together by hand.
  • A bowl
  • A selection of spoons, spatulas, and smaller prep cups/beakers.
  • Some sort of hard-sided mould (technically optional, but preferred)

How can I customize this bar?

The easiest way to customize this bar is by switching up the fragrance oil (or essential oil). You can also use a different light-to-midweight liquid oil. These changes won’t throw off the formulation, so have fun with them!

I also had fun incorporating a tiny amount of water soluble dye into these bars as I was developing them (this is how I distinguished between all the different versions I made!). If you want to include some dye, weigh out about half the distilled water, add a super tiny amount of dye (roughly one or two grains of sugar—so little that it is highly unlikely to register on the scale), and then add the rest of the water.

I used a teal blend dye for the bars in the video and paired it with Baja Cactus Blossom fragrance oil.

What if I want to customize it even more?

The wet/dry balance of this bar is key to its success, and changing up the dry ingredients (by using a different starch/flour or dry surfactant) will throw that balance off. This isn’t a disaster, but it will require you to do some re-formulation to determine how much more (or less) liquid you need to create a workable dough.

If you do find yourself needing to adjust the wet/dry balance, I recommend erring on the side of a wee bit too dry vs. too wet. I found that wetter doughs created bars that tended to crack as they dried.

How long do I need to age this shampoo bar?

3–5 days; err on the side of longer if you live somewhere humid. These bars are relatively delicate when fresh, but get really hard once they’ve dried out!

Learn more: How long do you have to age a shampoo bar?

Can I use this shampoo bar as a body wash?

Of course! I love working this bar up with a loofah—it creates amazing lather and leaves my skin feeling silky and fabulous.

Where can I get the ingredients for these bars?

YellowBee has put together a kit of most of the ingredients you’ll need! It contains the Sodium Lauryl Sulfoacetate (SLSa), Cocamidopropyl Betaine, Optiphen™ Plus, and fractionated coconut oil for just $23.52CAD (~$17.77USD at time of writing).

You have the option to add on fragrance(s), mould(s), and dye(s) if desired.

The only ingredients that are missing are the distilled water and the rice flour, both of which you should be able to get from your local grocery store.

You can find the kit here!

Relevant links & further reading

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Simple Sulfate-Free Shampoo Bar

Dry phase
144g | 60% Sodium Lauryl Sulfoacetate (SLSa) (USA / Canada)
33.6g | 14% rice flour

Wet phase
9.6g | 4% distilled water
24g | 10% Cocamidopropyl Betaine (USA / Canada)
3.6g | 1.5% Optiphen™ Plus (USA / Canada)
1.2g | 0.5% fragrance or essential oil
24g | 10% fractionated coconut oil

Put on your dust mask (respirator) and nitrile/latex/rubber gloves. This is not optional; if you do not have a well-fitting respirator, purchase one before making these (or any) shampoo bars.

Weigh the dry phase into a bowl and stir. Add the wet ingredients and combine to create a smooth dough. I usually begin with a bit of stirring before getting in there with my gloved hands to work everything together; I recommend keeping the mixture in the bowl rather than turning it out onto the counter.

Once the mixture is uniform, shape it into bars. I recommend hand squishing the dough into a hard-sided mould; I used a cute flower mould, but a 1/4 cup measuring cup would work well.

Leave the bars to dry for 3–5 days before using.

To use, massage the bar into wet hair to work up a lather, and proceed as you would with any other shampoo. This also makes a great body wash if you work it up into a lovely lather with a loofah. Enjoy!

When made as written, the pH of these shampoo bars comes out to around 5.5–6, which is great.

Shelf Life & Storage

Because this shampoo bar will regularly come into contact with water, I recommend including a broad-spectrum preservative to ward off microbial growth. With good manufacturing practice and proper preservation, this formulation should last at least a year. In the event you notice any change in colour, scent, or texture, chuck it out and make a fresh batch.

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 240g.
  • 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 Sodium Lauryl Sulfoacetate (SLSa) or rice flour/starch. If you change these ingredients you’ll throw off the wet/dry balance of the formulation and you’ll need to do some re-development work to get things to work.
  • You can substitute another lightweight oil like sweet almond, grapeseed, or sunflower seed instead of fractionated coconut oil. You could also try an ester, like Isoamyl cocoate or Neossance® Hemisqualane.
  • If you’re like to use a different preservative, please review this FAQ and this chart.
  • If you’d like to incorporate an essential oil, please read this.
  • For an unscented bar, simply replace the fragrance with more fractionated coconut oil.

Gifting Disclosure

All ingredients were gifted by YellowBee.
Links to Amazon are affiliate links.