Home Cosmetic Science Talk Formulating SCI shampoo bar recipe too soft/mushy

  • SCI shampoo bar recipe too soft/mushy

    Posted by Illidan on May 9, 2023 at 3:49 am

    Hi everyone!

    I am a beginner and a not successful one at that. I have three batches that failed because they are too soft. I tried different ingredient combinations and percentages and even my most successful batch that was able to retain form would meltdown under water.

    My idea is to have a simple vegan/natural shampoo bar that would work on all hair types for first wash with minimal benefits for oily and dry hair, and then have a “specialized” shampoo bar for the second wash that I can choose if my hair is dry, oily, damaged…

    In my latest failed batch I used:
    SCI powder 50%
    Coconut oil 20%
    Jojoba oil 10%
    Tapioca starch 10%
    Corn starch 4%
    Vegetable glycerin 6%

    I read somewhere on this forum that I shouldn’t be using glycerin, so might try another batch without it.

    What changes could I make to the recipe? The other ingredients I have are: shea butter, aloe vera gel (10x concentrated), neem oil, argan oil, and I was planning on getting coco betaine for more bubbles. I am willing to change the whole recipe if needed.

    Any help or pointers on how to get the recipe to at least retain shape would be amazing.

    • This discussion was modified 1 year, 1 month ago by  Illidan. Reason: Added some changes
    kot replied 1 year ago 7 Members · 22 Replies
  • 22 Replies
  • Illidan

    May 9, 2023 at 5:14 am

    I made a new batch and I used:

    SCI 50grams 66.67%
    Coconut oil 10 grams 13.33%
    Jojoba oil 5 grams 6.67%
    Tapioca starch 5 grams 6.67%
    Distilled water 5 grams 6.67%
    Lavender oil 5 drops

    I realize now that in my previous attempts I most likely didn’t use enough SCI, and used too much oils as the result of this batch was solid 3-5 minutes after mixing everything in. Now “all” that’s left is to wait for it to harden and remove it from the mold to see how it holds up.

    Now what I’d want is to add to the recipe is coco betaine for more bubbles and make the yield more liquidy as to fill the mold properly. But that’s a test for another day, and if anyone has further suggestions on changes that I can make to the recipe I’d highly appreciate it! 🙂

    • luttie

      May 13, 2023 at 11:03 am

      Reduce oils to a minimum. If they are still mushy, try cetyl alcohol, stearic acid, soy wax or any other good hardener. From 1-15% the feeling and processing of the bar can vary but it shouldn’t be too bad.

      MY first trials had about 5% oils and 5% butters but now I see it wasn’t a quite good idea, lol.

      You can substitute the water for cocamidopropyl betaine. I’ve used it up to 13% without problems (but was using about 13% of hardeners such as cetearyl alcohol or stearic acid).

      Since you are measuring everything in grams and making a quantity big enough to be weighted (100g) I recommend you to measure the mass of this “5 drops of lavender oil” to make things reproducible.


      - I still thinking you have way too much oil (about 20%)

      - There is no need to include many different oils in this initial learning phase, just pick one (the cheapest) try different levels (3%, 10%, 20% [you’ve got this 20% already]). Then substitute it for others partially and see what changes. Probably not much.

      - Do knockout experiments. I see you removed glycerin! It weakens bars greatly and took me quite a time to discover it was the problem with mine.


      ~ 50-70% SCI

      ~ 0-20% CAPB

      ~ 0-15% cetearyl alcohol or cetyl alcohol (it WILL supress foam, I find stearic acid better but generally gives a brittle appearance so you may need to combine it with something else)

      ~ 0-15% starch

      ~ 0-7% oils, butters, fragrance, preservative

  • gordof

    May 9, 2023 at 8:03 am


    I would suggest to you if you are new to formulation go to the basic Internet Compendiums for Formulations. Of course this side is a good way to clarify your problems. but you can use the Basic Formulations from suppliers of Raw materials or Formulations that are available on the internet.

    For Example, you can search on Prospector and filter for formulations Find Shampoo bar for Personal Care & Cosmetics applications, search data sheets, MSDS and request samples | Prospector (ulprospector.com)

    and you find several basic formulations to look at. eliminate all the chichi ingredients like Plant extracts or anything similar and just look at the ratio of the main raw materials to analyze in which amounts your ingredients should be used.

    Other sides you can look at


    Chemicals Marketplace - ingredients & raw materials - Knowde

    and then the fun of experimenting and finding the solution starts.

    PS You may be a new formula but you are not bad just because it took you 4 Tries to get to a solution sometimes Formulators need 50 and more Triess to be satisfied with their product so don’t be so harsh on yourself and try to enjoy the journey of learning something new about a new area of development you don’t know a lot right now.

    May Elun be with you Illidan :)????

    • Illidan

      May 9, 2023 at 10:24 am

      Hi Gordof! Thanks for your reply. Those sources look great! I will have to read further into them tomorrow.

      And you’re right, 4 attempts is not a lot but I’m just impatient I guess. 🙂

      Though I am happy to announce that the last batch I made and posted here looks great. It hardened enough to be removed from the silicone mold in 3 hours and it looks and feels great! Can’t wait to try it out when it dries completely.

      It’s a great starting point if I can say so for myself, and I can’t wait to build and expand on top of it!

  • mikethair

    May 12, 2023 at 9:52 pm

    I have been formulating products for many years, including shampoo bars. We were manufacturing shampoo bars for our own brand, plus Private Label brands globally. With the current focus on plastic waste, shampoo bars can be a good seller.

    You have done only four test bars? Crikey, with my first bars it took me a year to finally get a formulation to where I want it. Now, with the basic shampoo bar formulation perfected, it’s a lot quicker when I formulate Private Label orders taking into account the client’s requirements.

    And with soap, you have the added complication of cure time. In our case, we cure soap bars for 30 days in a controlled temperature and humidity in a purpose-built cure room. And at the end of curing, we then test the bars. The quality of curing can impact significantly on any type of soap bar, including shampoo bars.

    Also, for every test batch I record all data in Excel including the Batch Manufacturing Records (BMR). And it is these records that become important in soap bar testing and re-formulating.

    • luttie

      May 13, 2023 at 11:09 am

      I can only agree and cry ????

      My first shampoo bars took about 3 months to be barely usable (and I mean barely). It was so hard to make it work that for sometime I tried to make normal soap… After sometime I got a better mess (from the real, acidic, surfactant-based shampoo bars) and was trying to improve from there. By this time they were play-doh like when hot and needed to be molded or pressed (molded versions would be slightly “clumsy” and rustic).

      Suddenly I was asked to make them REALLY pourable (almost like a candle) which took me many months. I managed to get something usable but needed to sacrifice the feeling and foaming so it wasn’t worth it really. The bars were quite glossy and pretty though :(((

      Since then I’m always searching ways to make it pourable and more processable. In many facebook and forum groups people claim to have “pourable” formulas but they are just like my “messy”: a very thick cream that you can sort-of-fill a silicone mold with.

  • mikethair

    May 13, 2023 at 5:21 pm

    I find it interesting that some are saying “Reduce oils to a minimum.”

    Coming from a soap bar production mentality, our approach was exactly the opposite. We used all oils, and zero synthetics.

    Our formulations included a mixture of hard and soft oils: Coconut (H), Olive (S), Rice Bran (S), Castor (S), Avacardo (S), Palm (H), and Palm (H). The challenge was to adjust the quantities of each oil to produce the shampoo bar you wanted. And this takes time, given that each bar is cured in a temperature/humidity-controlled environment for 30 days before we evaluated the shampoo bar.

    Also in the mix were small amounts of Pomegranate oil, Horsetail extract, Nettle extract for their benefits to hair.

    And finally, a fragrance blend of essential oils.

    • ozgirl

      May 15, 2023 at 6:57 pm

      @mikethair The oils in this bar are not being saponified they are being added as some form of “conditioning”. All oils do in a syndet shampoo bar is reduce the foaming and cleaning ability of the bar.

      I prefer syndet shampoo bars with no oils and to save the oils for the conditioner.

      • mikethair

        May 15, 2023 at 8:20 pm

        Hi ozgirl,

        What you say is not correct. As specified in our batch manufacturing records, the coconut, olive, rice bran, castor, avocado, and palm oils are weighed and mixed, then saponified. Then small amounts of pomegranate, horsetail, and nettle are then added before the bar solidifies.

        I should also add the saponification numbers for the coconut, olive, rice bran, castor, avocado, and palm oils were determined from the CoA provided with each oil, and the correct weight of NaOH was determined and then added.

        Further, before we finalized the formulation we did a number of trials with the mix of coconut, olive, rice bran, castor, avocado, and palm oils, and in our laboratory we checked that there was no excess NaOH.

        • ozgirl

          May 15, 2023 at 8:45 pm

          @mikethair you are referring to a saponified soap based hair shampoo bar rather than a syndet shampoo bar which the OP is making. We are talking about two different things. I understand that there is some level of superfatting (excess oil) in soap based bars but if you have too high of a level of oil even in soap based bars there will be some reduction in foaming. In the OP’s original post the oil level was 30% compared to only 50% surfactant which may inhibit foaming.

          We might have to agree to disagree on this one. ????

          • mikethair

            May 15, 2023 at 8:57 pm

            Hi ozgirl,

            When you say “if you have too high of a level of oil even in soap-based bars there will be some reduction in foaming,” this has certainly not been our experience. The bars foam beautifully. And again it’s all to do with the selection of oils on which we spent many many many months and multiple trials. We usually do the trial bars in 1 Kg moulds. At the production stage use 12 Kg moulds, and five of these in each batch.

            And I agree, “We might have to agree to disagree on this one.” Maybe someone will learn from my alternative approach. As a chemist and scientist, I like to escape the ordinary. It kept my Private Label customers globally coming back.

            Thanks ozgirl from an oz guy.

            Kind regards,


    • kot

      May 20, 2023 at 8:49 am

      Hi Mike, as Oz girl already said- the shampoo bar is very different product. And the soap bars are actually cannot be used as a shampoo bars. The soap is a soap, no matter what you call it, and it is fa-a-ar away, or rather has nothing similar to a shampoo bars. Hence the formulations are different and the amount of oils will be different. As for “We used all oils, and zero synthetics.”- and what did you use to saponify your pure oils with?????

      • mikethair

        May 20, 2023 at 9:32 am


        I’m sorry, but it is a shampoo bar because that’s how it has been formulated. And yes, it is a soap. The formulation has oils that we would not use in regular soap bars. And as a result, it is a very different product. After 20 years of producing regular soap bars, we can tell the difference!!!

        And more importantly, our Private Label customers globally loved these shampoo bars.



        • kot

          May 20, 2023 at 9:45 am

          With all respect, No, it is not a shampoo bar, i am sorry….

          • mikethair

            May 20, 2023 at 4:36 pm

            How would you, therefore, define a “shampoo bar”?

            • kot

              May 20, 2023 at 11:40 pm

              Well, i think i could try to answer with just two letter….for now -PH

            • mikethair

              May 21, 2023 at 1:09 am

              In my opinion as a chemist, defining a shampoo bar simply by pH is an oversimplification.

              So I ask you again, what is the definition of a shampoo bar?

  • chemicalmatt

    May 16, 2023 at 10:11 am

    I have to add here: when I was a teenager I was ridiculed for washing my hair with a bar of soap. My sister schooled me on this: “never heard of shampoo before, idiot brother mine?” Now we have come full circle to being “influenced” to use a solid state shampoo, which is chemically equivalent to that bar of soap whether syndet or saponified. Next up: bell-bottom pants and Nehru jackets for the lads. ????

  • Illidan

    May 22, 2023 at 9:28 am

    Oh wow, lots of replies. Really sorry for abandoning the post as I didn’t expect a lot of conversations from this.

    In the past 10 days since I made this post I was learning and experimenting but it’s still not optimal as I’d want it to be. But reading replies I see that I shouldn’t be disheartened as it takes months before a good combination is found. I was lowkey hoping to get a formula I’d be satisfied with rather fast as the attempts are going out of my pocket and some materials aren’t cheap. ????

    I changed my recipe a bit after reading on more things and I abandoned the idea of having a “pourable” recipe and I am getting a custom 3D printed soap/bar press.

    The formulation I posted earlier was the best one so far as it was shedding 1-2 grams for two hair washes, but SCI is kinda expensive where I’m from so I experimented a bit but I realized that I have to have over 50% of SCI for the bar to be solid. The best formulation I came up so far is:

    <google-sheets-html-origin></google-sheets-html-origin><google-sheets-html-origin></google-sheets-html-origin>SCI powder | 45 grams | 56.25%
    Coconut oil | 8 grams | 10%
    Jojoba oil | 4 grams | 5%
    Carnauba wax | 5 grams | 6.25%
    Coco betaine | 9 grams | 11.25%
    Cetearyl Alcohol | 8 grams | 10%
    Benzylalcohol DHA | 0.6 grams | 0.75%
    Lavender ess. oil | 0.4 grams | 0.50%

    The mixture during preparation is like soft mash potatoes and once it cools a bit it’s like hardish mash potatoes and I will have to be content with that I guess. I washed my hair with it twice and that spent 2.3 grams of it which is good but I am not shampooing like crazy like some might. So there is definitely still work to be done.

    I was thinking of ditching carnauba wax as some other formulations came out sticky or soft and I am suspecting it’s because of it. ????

    Even though I ditched Tapioca Starch which was really expensive, I am climbing back to the original price point because of SCI and other ingredients now. ????

    @luttie I really appreciate your insight and suggestions! I’m thinking of reducing oils further now and increasing coco betaine and cetearyl alcohol instead. What do you think of my recipe in this post? I ditched Tapioca Starch and thought that carnauba wax would hold it, but that might have been a mistake. Would you recommend any other substitutes for tapioca starch?

    • luttie

      May 24, 2023 at 8:34 am

      Where are you buying your tapioca starch from? I live in Brazil so I can use food grade which is VERY cheap (like 8 BRL (about 1 to 2 US$) per kg). The cosmetics “tapioca starch” version, tapioca pure (which I think is not that different really, maybe it is more relevant in formulations with water) is about 30x more expensive.

      Here are my recommendations:

      1) You can try cornstarch, it shouldn’t be that different in this case and it is used by many brands. I’ve used it once or twice and couldn’t spot any difference from the tapioca version despite being more expensive (for me). I’ve seen some bars made with wheat flour too. Give it a try. Use the versions without too many stuff (like baking soda, vitamins).

      2) I do not recommend loading up your bar with so many oils and waxes… This may be the reason why you need to use about 2g per wash I guess.

      I would reduce jojoba oil to 1% and coconut to 2%.

      3) In my (limited) tests, carnauba wax impacted less the foam than cetyl or cetearyl alcohol i.e. it was better for the shampoo. I didn’t like candelilla wax because it wouldn’t solidify in a lotion bar trial (not sure why though) so I kept it out of shampoo bars tests. Are you sure you’re using carnauba and not candelilla?

      Usually cetyl/cetearyl alcohol gives a better appearance than stearic acid and waxes and increase shower stability (at the cost of reducing foam). I like to have >20% of things that will be liquid while hot so it is easier to process the paste.

      If your carnauba source is expensive (I guess it is because the tapioca was) you may try other hardeners that are (in my opinion) better for this usage and cheaper, such as stearic acid and glyceryl stearate.


      So my recommended starting point is:

      SCI 55%

      Starch - 18.75%

      Coconut oil 3.5%

      Jojoba oil 0.5%

      Coco betaine 12%

      Carnauba wax 4%

      Cetearyl alcohol 8%

      Benzylalcohol DHA | 0.6 grams | 0.75% (didn’t change)
      Lavender ess. oil | 0.4 grams | 0.50% (didn’t change)

      Please note that with more powders and less oils the formula may be more difficult to mix and more prone to “cracking” so you need to adjust from there.

      Do knockout tests[https://chemistscorner.com/using-knockout-experiments-to-reduce-formula-costs/%5D. Remove the carnauba, cetyl and oils one by one. How do they affect the processing and final product?

      The gruum shampoo bar [https://www.gruum.com/product/har-shampoo-bar-fragrance-free-50g/] for instance only has 3 ingredients: SCS, coconut oil and water.


      -> Just out of curiosity, this 0.5% lavender E.O. is enough to give a nice fragrance when washing your hair? I’ve been trying from 0.5 to 2% in my bars and <1% fragrance was so faint… The only exception were (1) a great fragrance house sample and (2) ylangylang EO.

      • Illidan

        May 24, 2023 at 9:40 am

        Thanks for your reply!

        I’m from Serbia so buying things from here and I have to go for chemistry level tapioca starch as there is no food grade ones sold here.

        And it is carnauba wax. It’s about $3.2 per 100 grams so that is inexpensive when compared to the amount I need. While tapioca starch is $11 per 100 grams. ????

        I like the example recipe you sent and I will try it right after posting this. Got my 3D printed mold/press as well so excited to try that too. 🙂 Though originally I was planning on removing the wax completely. Though I can leave that for the knockout tests (thanks for the link!).


        0.5% of lavender essential oil ain’t really enough. It’s there, but really faint. I guess I’m just putting that much as a placeholder for now. There is a slight fragrance to it, but it’s not enough. I also ordered some fragrance oils to test in some future recipes.

Log in to reply.