Shampoo Bar With Castor Oil

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Making shampoo can be a tricky business, but did you know that DIY shampoo bars are actually super easy to make? It’s the liquid shampoo formulations that can be tricky to crack, especially if you want to keep it natural.

But I found switching tact to formulating shampoo bars to be a much easier experience all around. From designing a formula to using the finished product, it’s just so much better (in my opinion, of course), take a look and see what you think.

shampoo bar with castor oil

What Are Shampoo Bars?

So, what exactly is a shampoo bar, and how is it different from other kinds of shampoos? Well, the most obvious difference is that shampoo bars are solid. More specifically, they’re solid cleansers formulated with surfactants, liquid oils, solid oils (such as coconut oil or cosmetic butter), and powdered ingredients.

They are not, however, true soaps. While you will find saponified soap recipes on the web labeled as shampoo bars, I would urge caution when trying them. Saponified soap is terrible for hair, and no amount of superfatting can help.

Instead, I opt for natural detergents, such as SCI powder and Cocamidopropyl Betaine. These are gentle surfactants that provide excellent cleaning and foaming action.

Furthermore, because our formulation doesn’t require saponification, we have way more control over the pH of our finished product. So don’t worry, no need to worry about acid rinses!

So, let’s take a closer look at all the different components we need to put together an awesome shampoo bar.

Ingredient Spotlight

Measure and combine wet ingredients for a castor oil shampoo bar


Our surfactants lend their cleansing and foaming properties to our shampoo bar. We’re using three for this recipe, so let’s break them down:

Sodium Cocoyl Isethionate Powder (SCI )

  • A natural mild surfactant that is known for its mild cleansing properties, helping to remove dirt and oils without irritating the scalp. It comes in powder, grains, or solid form. We will be using the powder, so we do not need to melt it.
  • It produces a rich and stable lather with great foaming properties. It can be used as a stand-alone surfactant or teamed with others to help maintain a good pH level.
  • Using it in a shampoo bar will bring some great conditioning properties, helping to maintain the scalp’s moisture balance and leaving the hair feeling soft and clean.

Sodium Lauryl Sulfoacetate Powder (SLSA)

  • Should not be mixed up with SLS, which can be irritating to the skin. SLSA comes in fine powder, grains, and noodles. We will be using the powder so that we do not need to melt it. 
  • SLSA is another super mild surfactant that’s been derived from natural sources like coconut and palm oils. It gives a fantastic, lasting lathering to the shampoo bar. Paired with the SCI, the result is a super foaming mild, non-irritating shampoo bar.

Cocamidopropyl Betaine

  • A natural mild surfactant that is best suited as a co-surfactant. When used with other surfactants, it helps produce a milder bar with a rich, long-lasting lather.
  • This surfactant differs from our others, as it’s a liquid rather than a powder. Therefore, we’ll need to add it alongside our other liquid ingredients. Take a look at my recipe card below to learn exactly when and how to add all of these ingredients.

This team of natural, mild, yet powerful detergents will whisk away grease and grime, leaving your hair sparkling clean.

Oils, Humectants & Aromatics

As much as our surfactants are mild and gentle on hair and scalp, we still want to include ingredients that will nourish as well as cleanse. No matter how mild a surfactant is, if it’s not properly formulated alongside an emollient, the hair can become excessively dry and straw-like.

So, I’ve opted to use Castor Oil for this recipe. Castor is a great carrier oil that has amazing properties for your hair. It helps to improve blood flow to the scalp, which can boost hair growth for thicker, more voluminous hair.

To make it even more luxurious, I also added my favorite humectant, d-Panthenol. It’s deeply hydrating, helping to soothe, nourish, and plump the skin cells of the scalp. I’ve included some Wheat Protein, too, which isn’t a humectant but will provide fantastic moisturizing benefits as well. It also restores hair elasticity and provides a beautiful gloss.

And because we want the hair to smell gorgeous, too, we can include an aromatic oil of your choice. I’ve opted for an essential oil, as they can provide further therapeutic benefits, too. But you can use a fragrance oil if you prefer.

Lavender Essential Oil, for example, is deeply soothing and healing. It’s also packed with antioxidants, helping to relieve the scalp of free radicals. Research suggests that oxidative stress could be a significant contributor to greying and balding hair, as well as other symptoms associated with hair aging.

So Why The Arrowroot Powder?

Simple! The arrowroot powder helps us maintain the right balance between liquid and solid. Without it, we wouldn’t have a solid bar; it would be more of a sticky paste.

Arrowroot powder doesn’t provide much therapeutic or cosmetic benefit for our hair. But it does help to improve the creamy texture of the bar much better than other powdered ingredients I’ve tried.


  • Powdered surfactants: We don’t recommend substituting these surfactants as the bar may end up too soft, and/or the pH of the finished bar could be too high. At a push, you could try using all SCI powder. This would make the bar more natural, and the pH should remain stable.
  • Arrowroot Powder: Another starchy powder, such as cornstarch or rice starch, should work.
  • Panthenol powder: allantoin would be a good substitute here, or you could leave it out.
  • Cocamidopropyl Betaine: Coco glucoside or decyl glucoside would be a decent substitute, but they have a higher pH, so the formula would need to be adjusted. Add around 0.25g of citric acid with the dry ingredients. This should keep the shampoo bar at a good pH range. 
  • Castor Oil: Any carrier oil would work well here.
  • Wheat Protein: another protein such as rice or a green tea extract would be nice.
  • Lavender Essential Oil: Any essential oil or fragrance

A Note About pH

Provided you follow my recipe, you shouldn’t have any problems with pH. I’ve chosen detergents that are mild and low in pH (in comparison to other surfactants). However, if you make substitutions to these, you might want to test the final pH of your bar. Check the notes in my recipe card to learn how to do this.

shampoo bar with castor oil

Lavender Shampoo Bar With Castor Oil

I found switching tact to formulating shampoo bars to be a much easier experience than designing a liquid shampoo, take a look at this one I made using castor oil.
5 from 1 vote
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Prep Time: 5 minutes
Active Time: 25 minutes
Total Time: 30 minutes
Yield: 100 g
Author: Angela Wills

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  • Before you begin, put on your face mask. Place all your drying ingredients into a bowl and stir.
    38 g Sodium Cocoyl Isethionate, 24 g Sodium Lauryl Sulfoacetate, 13 g Arrowroot Powder, 5 g D-Panthenol Powder
    Place all your drying ingredients into a bowl
  • If using, add the mica to the dry ingredients. I find micas can differ in color, so I prefer to eyeball the amount I'm adding. Remember that the mica will be three times darker once the wet ingredients have been added.
    Mica Powders
    add the mica to the dry ingredients
  • In a separate small beaker/container, Add the Cocamidopropyl Betaine, Caster Oil, glycerine, wheat protein, lavender essential oil, and the preservative. Stir to combine.
    10 g Cocamidopropyl Betaine, 8 g Castor Oil, 2 g Glycerine, 1 g Lavender Essential Oil, 1 g Preservative, 2 g Hydrolyzed Wheat Protein
    Measure and combine wet ingredients
  • Pour the wet ingredients into the bowl containing the dry ingredients.
    Pour the wet ingredients into the bowl
  • Use the spatula to bring the ingredients together. You are looking for a crumble-type consistency.
    Use the spatula to bring the ingredients together.
  • Once you have the correct consistency that is not too sticky so that it sticks to your hands, you can use your hands to bring it all together. Give it a good knead to ensure everything has been fully incorporated and you have the consistency of play dough. If the dough is too sticky, you could add more arrowroot powder or more glycerine if it is too dry.
    Give it a good knead to ensure everything has been fully incorporated
  • We can start filling the mold when you have a good flexible dough. I like to push the shampoo dough in a bit at a time to make sure it is getting into all the corners and sides. You can place the whole dough ball in and give it a good squish down.
    start filling the mold
  • For a smoother finish, try placing a piece of wax paper over the dough and smoothing it down with the palm of your hand. You can then place the mold into the freezer for a couple of hours to harden.
    try placing a piece of wax paper over the dough and smoothing it down with the palm of your hand
  • Once the shampoo bar has hardened, you can remove it from the mold. Be patient and begin by tugging at the edges of your mold. The shampoo bar will need to dry out and harden for a good few days before you can use it. I found most bars take around a week before they are ready.
    Once the shampoo bar has hardened, you can remove it from the mold.


    • This shampoo bar can be used as an all-over soap as well as a shampoo bar. 
    • To check the pH. Unfortunately, the bar needs to be solid, so you shave 1g from it and dissolve it in 9g water. Adjust the sample if needed (5 to 6pH), then multiply this by the bar’s weight. In this case, the bar is 100g, so if the sample needs to be adjusted by 0.002, we could multiply this by 100 = 0.2, so we would add 0.2g of citric acid to the next bar we make.
    • You must wear a face mask whilst working with powder surfactants.

How To Use

First of all, don’t forget to let your bar harden. I get it; when I make something new, I’m excited to use it, too. But if we don’t give it those two days to harden, you’ll find it melts away in the shower or bath way too fast.

So, once it’s nice and stiff, we can take it in the shower with us. Just soap it up a little, and then rub it into the roots of your hair, working to the tips. When your hair has enough lather, you can put the bar to one side and really massage your scalp. This helps to remove dead skin cells and prevent the build-up of dandruff.

Then, rinse and repeat if necessary. You should follow this up with a good quality conditioner to nourish your hair further.

Final Thoughts

That is all for today, I hope this shampoo bar recipe has given you the inspiration you need to make your own at home. Trust me, it’s much easier than any other kind of shampoo making. In fact, I’m not sure just yet if I’d ever need to make a liquid shampoo again.

Let me know if you have any questions in the comments section below. I’m happy to help you troubleshoot any problems you encounter. Let me know how you like the formula too, and if you made any changes to customize it to your liking. I always love to hear about your experiences as formulators!

Have a blessed day, and I look forward to seeing you in my next post!

SCI Shampoo Bar With Coco Butter

If you’ve not tried making shampoo with surfactants before, this super easy SCI shampoo bar is a great place to start. The Cocoa butter smells great and adds beautiful moisturizing benefits.

Author: Angela Wills

Title: Founder and Author - Savvy Homemade

Expertise: Beauty Recipes, Skincare Formulation, Soapmaking, DIY Crafts, Parenting

Angela Wills is an author, founder, and the driving force behind Savvy Homemade. With over fifteen years of experience, she brings a wealth of knowledge and dedication to every post she writes. She is fearlessly dedicated to creating tried and tested beauty recipes, skincare formulations, soap recipes, and many other DIY crafts that will work for everyone. Angela has a Diploma in Skincare Formulation, is a proud member of the Handcrafted Soap & Cosmetic Guild, and infuses each DIY product with her passion and expertise.

5 from 1 vote (1 rating without comment)

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