Home Cosmetic Science Talk Formulating liquid soap

  • liquid soap

    Posted by humblebutton on January 27, 2024 at 11:06 am

    I make liquid soap but I’m trying to make it less drying:

    Coconut oil

    Olive oil

    Castor oil






    Dilute with water

    Decyl glucoside

    Sulfated castor oil



    I’m looking for advice on how to make it less drying on hands. Suggestions about the order, different ingredients, etc welcome.

    I’ve never worked with Decyl glucoside, HEC, or aloe so I didn’t know where to put them in the phases. I tried to look it up but it’s difficult to find information on liquid soap making. It’s mostly all about using Castile soap as a base or making bar soap.

    Thanks in advance!

    mikethair replied 1 month ago 3 Members · 6 Replies
  • 6 Replies
  • mikethair

    January 29, 2024 at 12:34 am

    Ok, a few points here, based on my experience as the co-founder of
    a skincare manufacturing factory in Viet Nam and Malaysia since 2006. We manufacture and export to many brands globally.

    First, Decyl glucoside, and HEC are not required.

    Second, to make it less drying on the hands, we use a process called “superfatting.” In essence, you adjust your saponification formulation by reducing the amount of KOH to leave some of the oil unsaponified. It takes some experimentation and good record-keeping to get the balance right. And once you get it right, then use the same formulation repeatedly. Also, be careful of the quality of ingredients used. They must be consistent.

    Please feel free to message me if you need help.

    Kind regards,

    Dr Mike Thair.

    • humblebutton

      January 29, 2024 at 7:25 pm

      Thank you so much for your reply! I ended up going back to my old formula that uses SLSA instead of Decyl glucoside. I just couldn’t get a good soap from the Decyl. Everything I tried failed to make it less drying. The SLSA does great with NOT drying out hands. I discovered today that the SLSA is easier to mix in if I dissolve it in part of the dilution water first before diluting to paste and then combine the dilution water with the paste as usual.

      I was trying the HEC because I had received concerns about the soap being too watery. If I add less water it’s a little too concentrated. Does the HEC affect how drying it it on skin?

      My usual paste ingredients are:

      Oils coconut:olive:castor 2:2:1

      water:glycerine 1:1


      Then I dilute with

      87-150% water + 2% SLSA

      Add 2% sulfated castor oil

      So, what I was trying to fix by trying the HEC was a more consistent thickness and less watery consistency. I was told the slip it provides is nice. I like the slip as well but I’m not sure if it’s impacting the soaps ability to lather well or not. The first test was at 2% which was way too much. The second was .5% which seems better but I think it’s affecting the clarity. It’s not making it cloudy but it’s causing a slightly textured look instead of the super smooth, clear-glassy type look, if that makes any sense. I tried stearic acid (I’ve never worked with it before) but I couldn’t get it to do much of anything. I may have been doing something wrong though.

      The other issue I was trying to fix and haven’t been able to yet, is that the feel after the soap is washed off. You know the feeling on your finger tips after you wash your hands with a bar of soap, almost a gritty feeling? My soap isn’t nearly as bad as bar soap, for sure, but that’s not a very desirable feeling for a liquid soap. I’ve gotten quite a few comments about that and I’ve felt it myself as well. I tried 1% and 2% aloe as well as 1% and 2% propylene glycol. I’m not sure how to get rid of it. I haven’t noticed any improvement with either of those ingredients.

  • abdullah

    January 29, 2024 at 11:51 pm

    All soaps are drying. It means no company has been able to make a soap that is less drying. So don’t waste your time on solving that problem.

    • mikethair

      January 30, 2024 at 12:28 am

      Hi Abdullah,

      With my experience as
      the co-founder of a skincare manufacturing factory in Viet Nam and Malaysia
      since 2006, I would have to disagree. It’s all about the soap formulation and superfatting. And one thing that our customers said was that our soaps were not drying. We exported soaps globally, and many (about 90%) were Private Label.

      In fact, I spoke to a long-term (10-year) Japanese customer this morning, and she made this point. She sells her soap to a very prestigious retail outlet in Tokyo.

      Therefore, I’m sorry, I will have to disagree with you in saying soap is drying.

      • abdullah

        January 30, 2024 at 9:14 pm

        Hi mike

        I just shared my experience because i haven’t seen or used any soap in our market that is not drying. Maybe we don’t have good soaps here ☺️

        • mikethair

          January 30, 2024 at 9:27 pm

          Yes indeed. I would agree.

          Many soap makers don’t spend enough time developing formulations. In my case, as a scientist, I applied full scientific rigour to developing our formulations. So it was a slow, methodical process. And including the time of having consumers test each batch, I spent at least 12 months before I was happy with the original formulations.

          And another factor is that I was operating in our GMP-certified factory. Here I developed the QC System and all of the Quality SoPs. What this meant was that record keeping during the development phases of our formulations was 100%, and so was reproducibility. All very important. And something that many overlook.

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