Cloudiness in liquid soap...

I have some liquid soap that I have made that has some cloudiness in the top 1/2 inch or so of the containers.  I have researched the issue and found two possibilities.  One might be that even a slight amount of "superfatting" the oil phase may cause this and that "superfatting" is not recommended in this type of formulation.  The other option might be that the cloudiness is coming from the fragrance not totally being emulsified into the liquid soap.   My formula is not "superfatted" and takes into consideration the 90% of the Potassium Hydroxide.  Now, another factor is pointing toward the fragrance issue and that is that a couple of the scents (fragrance oil) have no cloudiness in them!  Here is the typical ingredient list so that I make sure there aren't any other possible issues!

Ingredients: Water, Cocos Nucifera (Coconut) Oil, Oleic Acid, Ricinus Communis (Castor) Seed Oil, Potassium Hydroxide, PEG-150 Pentaerythrityl Tetrastearate, Glycerin, fragrance, Caprylyl Glycol, Phenoxyethanol, Hexylene Glycol

It was suggested using polysorbate 20 for the fragrance issue.  Do you have any other options or suggestions?

Amount listed were 1-20% from the MSDS sheet.  Do you have Any suggested amounts or ranges?

Is it better to do this when product is still warm from production or can this be used at room temperature?

Should the fragrance and Polysorbate 20 be mixed together before being "homogenized" into the mixture?

Thank you in advance for any suggestions or information you can provide!  :)

Regards, David
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  • I have been working with a bottle of liquid soap and adding small amounts of Polysorbate 20 to the batch and stirring it then letting it settle.  The first time I used a small amount, the second a bit larger and more today.  The cloudiness seems to be all over now but much finer than before and the top half inch of cloudiness is there but less obvious.  After today's addition, I hope I get better results but I won't know until tomorrow.  I've been searching for more info on the use of Polysorbate 20 (and 80) and have found a few things but most are from soapmaking boards or blogs.  I would prefer to get my info from a cosmetic chemist who works with formulas and has the background and knowledge needed to use the best approach in making any of my products.  The late Maurice Hevey was the first chemist I encountered on a message board and I quickly saw the benefits then Perry came along and I eagerly jumped aboard the ship!  If any of you have any input that are willing to share I would greatly appreciate it.  I want to make the best product I can! 
  • letsalcidoletsalcido Member
    edited March 20
    I’m developing a “natural” body wash with a castile soap base like yours, and having similar issues.

    My take on this is that you’re on the right track. But there doesn’t seem to be a straight answer to fix your formula. You’ll have to experiment, as all ingredients will have a different effect on micelle stability.



    These two bottles are from a “failed” experiment of a peppermint and menthol body wash.

    Here’s what I did: I tested 1:5 oil to PS20, at 1% essential oil in pure castile soap. This created a perfectly clear mixture. I tried a 1:2, also clear but it took longer to clarify. I decided on 1:2 since eventually I would achieve enough clarity and I only had a small sample of PS20.

    I did a 500g batch (300g is castile soap) and added my fragrance and PS20. All good till then, fairly clear after mixing. I could tell when left at rest it would completely clarify. I added 100ml of 5% salt solution. It broke and turned creamy/white. I continued with my recipe and tried to thicken it more with  Cocamidopropyl Betain. Still white.

    I did another 500g batch, but instead of adding the sodium first I added the coco(...) betain. Broke before I added the sodium.

    So I tried to fix it. I figured that the electrolytes and anything that may alter the viscocity of the soap (preservative, type of essential oils, menthol) is actually putting ionic stress on the micelles and eventually causes it to break. But this is not irreparable, I tried to fix one of the 500g batches and basically halved the concentrations of essential oil and polysorbate by doing 250g of my broken batch and 200g of fresh castile soap + 50g of other stuff. That immediately turned clear again, and It became thicker too (hello micelles!). I added glycerin (10g) and made it even clearer, but more watery. Added the required Phenoxyethanol amount to get it to 1% and i turned a bit thicker but not quite there. So I adjusted it further with Coco(...) Betaine (5g?) and 1g of salt in Q.S. water. Left bottle in the pic was the first fixed batch. The one on the right, I did basically the same procedure but I tried adding a tad bit more salt (bad idea) and it turned a bit more opaque but still seems to be that it will be stable and won’t separate, it’s just not emulsified fully like the clear one.

    Another pic of another creamy looking batch I fixed this morning which has orange essential oil (citrus oils are hard to get clear apparently):



    What I learned from this:
    * Anything that alters the viscocity of your soap (interacts with micelles) can break the emulsification of your essential oils and make it look creamy.
    * even without essential oils, your soap will turn creamy and slimy if too much sodium is added. 
    * if it looks creamy and has oils in it, it will separate eventually
    * Each essential oil is different and will behave differently.
    * Any other actives in your formula can destabilize it.

    If you are set on the preservatives and fragrance you want to use, I recommend doing a “titration” to find the balance. You’ll notice that you may achieve a peak thickness before adding a single drop of anything and it breaking. 


    If you’re curious, my base castile is 60% Olive, 40% Coconut, approximately 1:4 oil to water ratio.

  • WOW!  Thanks for all of this "info" and observations and pictures!  It is becoming a bit more "clear" (pun intended) as to what all of the aspects are to take into consideration!   I am using essentials oils and also using fragrance oils and sometimes a combination of both so that should play a role in all of this as well!  I'm going to go over what you posted and reply when I have time to "absorb" (pun intended) all of this!  Seriously, I really appreciate your input and I am grateful for your help!   David

  • We successfully do a lot of liquid soap in large vats. A few points based on the comments above:
    1. Why would you add a preservative? Liquid soaps are self-preserving and are included in the ISO 29621 Cosmetics — Microbiology — Guidelines for the risk assessment and identification of microbiologically low-risk products. Under our local GMP regulations, we have Challenge Tested all new formulations and the results are excellent.
    2. During the in-process QC, our QC Manager does a  simple "saponification test" to ensure that the saponification is complete. This is recorded on the BMR.
    3. Our philosophy is "keep it simple." We make large batches of liquid soap bases using various combinations of oils, or just simply a coconut oil base, and an extra-virgin olive oil base. Once a batch is completed, we store for two weeks in jerrycans, then our QC Manager does a range of QC tests, and if OK, release the batch to our production crew.
    4. I can't comment on fragrance oils because we never use them.
    5. Yes, certain essential oils can cause cloudiness and increase viscosity. My advice, learn to identify these and avoid them. Also, in some cases, cloudiness may appear initially, then after a few days, clear.
    6. In the production phase where EO's are added, we leave the mixed batches sitting for 1-2 hours, and our QC Manager will evaluate before allowing the production crew to proceed with bottling.
    Hope the above is helpful. And my main advice is to keep it simple, the more gunk added is likely to increase clarity problems.

    Below is a pic of a nice clear liquid soap in our vat, ready to go into jerrycans.





    Dr. Mike Thair
    Cofounder & Chief Formulator
    Indochine Natural
  • letsalcidoletsalcido Member
    edited March 20
    Thanks for your input @mikethair!

    To address some of your comments:

    - I understand that soaps are “self preserving”, but it will depend on concentration. In the bodywash I’m formulating I must have < 12% soap (1kg of oil in a 5kg batch, not counting the glycerin that’s the byproduct and it’s only 60% of the final product). If you take a look at most shampoos and body washes they do use preservatives given the extremely high water content. I in fact I had a batch with only 0.2% citric acid and 0.1% EDTA (bad idea, it gelled like crazy) that had bacterial colonies growing on it after 2-3 weeks (easily distinguishable because it had gelled and it looked like a petri dish). Also, the pH of my liquid soap routinely tests ~5.5 (perhaps I’m using the wrong kind of strips, and haven’t invested in a pH meter).

    - Castile soap is easy to make, but in its pure form is very strong. It also lacks the cosmetic luxury that some people are looking for (thickness, natural fragrance, humectants). So I’m not trying to sell plain castile soap, but rather a more natural body wash. 

    Here’s my finished liquid castile soap. Pretty good clarity, but it’s hard to enhance it for that “luxury” feel.

  • letsalcido,  Your first two pics show one on the left side which looks quite nice to me even though you list them as "failed batches"!  The second pic shows two batches that are very similar to mine in color and they are fairly clear but not 100%.  The third attempt of mine yesterday on that one batch (that was made by adding fragrance oil to a "cold" batch that was 100% clear before adding the fragrance) had "cloudiness" at the top but now has it throughout the bottle but less dense and does look a little better today but I only put in the Polysorbate 20 in multiple drops each time just to see what would happen! 
    Mike, I think we are going for different markets so my customers are more concerned about consistency and skin feel which is why I chose the PEG-150 Pentaerythrityl Tetrastearate which has worked quite well and so far hasn't been affected by the addition of Polysorbate 20.  As letsalcido said, it is going to be something I will have to make work in whatever way I can find from batch to batch and fragrance to fragrance.  Letsalcido also mentioned using sodium (I am assuming as a thickener) but is one option that didn't appeal to me. 
    I would like to keep my products "all natural"  but that option isn't always the best option for the customers desire for just the right consistency and skin feel!  Interesting hearing about both of your production techniques.  I make mine early in the day, giving it some chance to sit in it's gel state which occurs fairly quickly with a fatty acid in the formula then it left to sit for a bit then water is added, left overnight then homogenized the next day with the addition of fragrance or essential oils.  Hopefully I can work this out and get that one "esthetic" part of the formulation correctly for a product that already does quite well as it is!  Thanks again, guys for your assistance! Letsalcido, nice earrings!  ;)
  • @David08848 thanks for the compliment and sorry if my redaction was confusing! The two green washes are made from a failed batch that looked extremely creamy. I split that batch in half and fixed them separately with slightly different amounts of sodium. Those two bottles are the result. 

    Same thing with the orange ones. Except I followed the same process for each so they look the same.

    I would say that sodium is “natural”. I actually am using sea salt. I’m sure there may be some other minerals in there, but overall it should give consistent results. I would think that marketing your body wash as containing “sea salt” or “pink himalayan salt” could be attractive to the consumer. You’d just need to adjust it to each type of salt and make sure it doesn’t react in an unexpected way. of course, you can thicken with something else. Just my 5 cents.

    In terms of process, I have been very impatient and mix all my additives to the castile soap within 5-15minutes from each other. I’m hoping to find a “fool proof” recipe that would be easy to scale up.
  • letsalcido, Thanks for the clarification!  Your putting forth the use of salt is making me think about it.  Glad you mentioned you used a solution.  Do you have a suggested range I might want to try or a suggested solution strength range?   I have been looking at posts here this afternoon and evening about liquid soap and found a post of mine regarding my procedure from 2016! 

    "Basically, my liquid soap is made by heating the oils, mixing the KOH with water in a plastic bucket until combined then adding the solution to the oils and stirring until saponified and it turns to a paste.  For me that takes about 10 minutes.  It is then covered and left overnight to make sure the saponification process is complete.  The next day the paste is weighed to determine the amount of H2O to be added, water is then heated then my thickener is added and stirred until dissolved, then the soap paste is added to the heated water and stirred then left to be dissolved by the heated water then covered. (glycerin can be added at this point if used).  Usually the by the next day the paste is totally dissolved and the fragrance can be added and it is weighed again to see if H2O needs to be added to bring it to the proper concentration reflected in the formula and it is then ready to bottle.  For this type of production a mixer is not needed."

    What concerns me is taking whatever I feel is right to correct this esthetic of my liquid soap and applying it to a large batch and being able to make it work!  I'm open for suggestions, my friend!

    David

  • @David08848 ; I just started making cosmetics/soap. I have a background in biochemistry but no industry experience. What I shared is what I have observed, experienced and found by doing some research online.

    I found a few sources, and this video has a great explanation for thickening soap with sodium. I believe she mentions that the maximum is 2% or you may break it (like I did by adding just a tad too much sodium) https://www.youtube.com/watch?v=y5z_zAnSEZg 

    It will be a matter or titrating until you reach the desired viscosity and documenting how much you used.
  • letsalcido,

    Just to recap, you showed two examples of your liquid soap in which you said on March 20th you used Polysorbate 20 to clarify them successfully and those are the pictures of the two green bottles that are above your comments about them?  The first one came out fine and to the second on you added salt which broke the emulsion.  On March 21st you said the two bottles of green you "fixed them separately with slightly different amounts of sodium".  So I am a bit confused.  Are you saying that the salt in small amounts can thicken a liquid soap and also give them some clarity and in larger amounts can either brake the emulsion and or cause clouding of the mixture?

    So does this mean that using salt in proper percentages can clarify and thicken a soap based liquid soap?  What about the Polysorbate 20?  Is that for clarification only or can that add to the thickening as well if not used in too high a percentage?  I just want to make sure I understand this before I go any further.  Thanks for your help!

    David

     


  • @David08848 ;

    The salt/sodium is specifically for thickening purposes. There’s a limit to how much you can use before it causes the soap to break/turn turn opaque.

    The polysorbate 20 is definitely needed for solubilizing your essential oils. The only essential oils I was able to use without it were peppermint and eucalyptus with menthol crystals (not sure if the menthol helps).

    I fixed two of my broken batches (not shown in any pictures) by diluting with castile soap 1:1 and adjusting the thickness with salt and coco betaine for each bottle. The pictures are the result of this. In the first picture I added slightly more salt to the half batch on the right, and it caused it to break.

  • @David08848 there is a blog post on this website that should help you figure out your salt curve.

    https://chemistscorner.com/why-does-salt-thicken-shampoos/
  • letsalico, Thanks for the clarification.  For the moment, I will stick with the PEG-150 Pentaerythrityl Tetrastearate because it has worked well and I still have a quantity of it to use up before I consider using salt but it is good to know the procedure!  I was planning on making a large batch then putting together very small containers to test with each scent I am considering using sort of like what is described in that link that alchemist01 posted from that Perry Romanowski guy!  (He looks so familiar!)  From my experience, I have found that fragrance oils can cause the same cloudiness as essential oils so if I can try each one with Polysorbate 20 in similar increments then record the results as suggested hopefully I can make sure that all scents have the correct percentages and give the best clarity possible!  Thanks, all of you!  I appreciate your help!  Looks like I'll be alone in my store over the next few weeks so that will give me the time to try all of this!
  • letsalcidoletsalcido Member
    edited April 2
    A few updates @David08848

    I ordered some PEG-40 Hydrogenated Castor Oil as it is supposed to be an even better solubilizer than Polysorbate 20.

    I also noticed that my soap is sensitive to temperature and gets very cloudy when cold. My uncle who has some experience with a shampoo he claims that Polysorbate 20 is cold sensitive, and solutions will turn cloudy. He had better success with PEG-40 HCO.

    I did a test and that was true, I put a clear solution at room temperature of E.O./Tween20 in water and it turned opaque. I doubled the concentration of Tween20 and it resisted cold temperatures but the amount I had to use was too high. 15% or so. I’m hoping PEG-40 HCO can be used at much lower concentrations for the same result

    Also, I didn’t know (newbie here) that liquid castile soap would turn very opaque (creamy) when cold. Is there a way to avoid this? Perhaps is the type of oils I used, and the solubility of the resulting soaps.
  • David08848David08848 Member
    edited April 3
    Luis, I really appreciate your input!  Your mention of PEG-40 Hydrogenated Castor Oil  rang a bell so I am starting to do some research and hopefully will find this available with one of the chemical companies here in New Jersey and New York so I can find a source and give it a try!  (I might even have a sample of it somewhere!  Also, I use Castor Oil in my formulation!)  

    I have found that in general liquid soaps can become cloudy on their own without a solubilizer when the temperature drops.  In my retail store here in New Jersey I have noticed differences in my liquid soap when the temperature starts rising in the Spring and lowering in the Fall.  They tend to stay clear in the Summer with a rise in temperature but I need them to be clear year round!
    It's helpful to hear your test experiences and with the small amount of experimentation I have had the time to do so far with the Polysorbate 20, I only have gotten small changes in the product. (and I wondered how much more I would have to add!)

    Without knowing the exact ingredients you are using in a liquid "Castile" soap it is hard to say.  This may have already been mentioned but liquid soap seems to perform the best when a zero percent superfat is used.  I did some research here and found a post about making liquid soap and the guy who was working on it said that he only used a 5% superfat and no one here picked up on it and mentioned that he might make out better with a zero superfat!  Sometimes, people see projects like these as being easy and "not rocket science" but this isn't always the case in my experience.  I have greatly appreciated your input and sharing, Luis!  Thank you!
  • So, as an update, I've been reading up on PEG-40 Hydrogenated Castor Oil and I went to the Protameen site, a local NJ company I've done business with for many years, and I see that they not only have PEG-40 but also 16, 25, 50 and 60!  I've only been looking up the 40 so I guess I can check with them and see what they suggest and do some research on the other options. I should have figured that it would come in various forms!  Life is a learning experience! :smile:
  • I saw that the PEG-40 Hydrogenated Castor Oil was "liquid to semi-solid" and the PEG-25 is listed as liquid so I'm getting the picture and I can see that most like the PEG-40 should be able to perform in the way that is needed... back to research!
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