Today we’re doing something a bit different; I wanted to walk you all through the experiments I did while I was working on last year’s Christmas Tree Body Wash as The Tale of the Curdling Body Wash. It was a really interesting puzzle that I worked at for quite a while—I managed to isolate the trigger, but I still don’t know exactly what is going on, so my only solution for avoiding the curdling is avoiding the trigger. I thought I’d share my process and my results, and maybe we can crowd source a better answer!
This story starts last autumn as I was wrapping up my Formula Botanica course work. I developed a simple body wash using Caprylyl/Capryl Glucoside and Cocamidopropyl Betaine. I wanted to increase the lather, and I remembered reading somewhere that Hydroxyethylcellulose could help with that, so I swapped the xanthan gum I had been using for some Hydroxyethylcellulose (HEC). Magic! Not only was the consistency of the body wash dramatically improved, but the lather became absa-freaking-loutely amazing. Swoon. I made a few versions (different scents and different colours), bottled ’em up, and headed off to Europe.
Here was the formula at that point:
8.00% Glycerine
2.00% Hydroxyethylcellulose70.50% Distilled water
12.00% Caprylyl/Capryl Glucoside
6.00% Cocamidopropyl Betaine0.50% Liquid germall plus
1.00% fragrance or essential oilProcess: Whisk together HEC and glycerin. Add water, surfactants, and colourants, stir gently. Heat in a water bath, gently stirring relatively frequently (~once every 2–3 minutes) until thickened. Remove from heat, stir occasionally until cool, stir in cool down ingredients.
Once I got home I needed to wrap up my Christmas series, and I’d planned a Christmas Tree Body Wash. My experiments from earlier in the fall were looking great and seemed like the obvious choice for the base for the Christmas Tree Body Wash. So, I whipped up two versions: one with an essential oil blend, and one with a fragrance oil, as I’d been doing for many of the Christmas Tree series. Everything seemed to go swimmingly until I went back to the bottled body wash after twenty minutes or so… and they had both separated. There was a thin, watery liquid floating on top and a blob of gelatinous goo at the bottom. What on earth? The original samples from my coursework were still stable—crystal clear, silky smooth, and definitely not separating curdled disasters.
This was roughly the formula at this point:
8.00% Glycerine
2.00% Hydroxyethylcellulose70.40% Distilled water
12.00% Caprylyl/Capryl Glucoside
6.00% Cocamidopropyl Betaine
0.10% lake dyes (blue + yellow = green)0.50% Liquid germall plus
1.00% fragrance or essential oil (essential oil version was fir balsam + peru balsam, fragrance oil was balsam cedar fragrance oil)
In this photo you can see the separation—the liquid floating on top and the blob at the bottom.
Thinking it might be my process I tried many different ways of mixing up the solution—cold hydrating the HEC, warm hydrating, hydrating without stirring, hydrating with constant stirring, cold mixing everything with five constant hours of stirring (thanks, KitchenAid stand mixer). No dice.
Up next was isolating ingredients, making the gel adding one ingredient at a time, stirring, and waiting between additions. The fragrance/essential oil quickly outed itself as the problem. I tried many different fragrances and essential oils, noted what happened, and cross-referenced the chemical components (click here to learn how to do that) to find the common element between all the fragrances and essential oils in the experiments that split. It was benzyl benzoate. Once I had a hypothesis I tested it, intentionally choosing fragrances and essential oils that did or didn’t contain benzyl benzoate and adding them to small samples of the unscented body wash. The scents I used that didn’t contain it were “black salt & cypress” fragrance oil, fir needle essential oil, and “citrus mist” fragrance oil. Boom. The hypothesis held.
So many different experiments.
Failure! You can see the thin liquid seeping out of the jelloid blob.
Success! No seeping.
So, at this point I know what is causing the curdling, but I still have no idea why. I decided to broaden the experiment. I tried a slightly different version using an anionic liquid surfactant (Sodium Laureth Sulfate, pH 7.5) instead of a non-ionic liquid surfactant (the Caprylyl/Capryl Glucoside), adjusting the amount of surfactant and water to keep the active surfactant matter the same. Hydroxyethylcellulose is non-ionic, so its charge shouldn’t be a factor, but who knows!
8.00% Glycerine
2.00% Hydroxyethylcellulose54.70% Distilled water
27.70% Sodium Laureth Sulfate
6.00% Cocamidopropyl Betaine
0.10% lake dyes (blue + yellow)0.50% Liquid germall plus
1.00% fragrance or essential oil
This experiment split/curled before adding any fragrance or essential oil, so in this one it’s the Sodium Laureth Sulfate that’s the problem. That’s… weird. Maybe the charge of the surfactant is part of it? I did more experiments.
I made a batch of the first body wash, but without the primary surfactant (the Caprylyl/Capryl Glucoside).
Experimenting with different surfactants.
I used a lake dye that shirts in different pHs so you can really see which ones are basic and which ones are acidic.
I then divided it up and added 15% of a variety of surfactants:
- Coco glucoside (non-ionic, pH 11.5–12.5)
- Decyl glucoside (non-ionic, pH 11–12)
- Disodium Laureth Sulfosuccinate (anionic, pH 5.5–6.2)
- Sodium Lauryl Sulfoacetate (and) Disodium Laureth Sulfosuccinate (anionic, pH 5.2–6.2)
- Sodium C14-16 Olefin Sulfonate (anionic, pH 8–9)
I chose these surfactants for the variety of charges and pH values, and because they’re all the liquid surfactants I own. They all have ASM values that are quite a lot lower than Caprylyl/Capryl Glucoside so it definitely wasn’t an even ASM challenge, but from previous experience I was pretty sure anything that was going to split would, regardless of ASM, as fragrances with 10% benzyl benzoate split as effectively as fragrances with 80% benzyl benzoate.
Without adding any fragrance of any kind, these were the results:
- Coco Glucoside: split, pH ~8
- Decyl glucoside: split, ph ~9
- Disodium Laureth Sulfosuccinate: stable, pH ~4
- Sodium Lauryl Sulfoacetate (and) Disodium Laureth Sulfosuccinate: tentatively stable, ph ~4
- Sodium C14-16 Olefin Sulfonate: stable, ph ~5
So… now the non-ionic surfactants are breaking things, and the anionic ones are fine. This is counter to my first two experiments, where the non-ionic Caprylyl/Capryl Glucoside was stable without fragrance, while the anionic Sodium Laureth Sulfate split. Thinking it might be pH (since the basic ones were splitting while the acidic ones seemed stable) I weighed out some of a successful unscented batch using Caprylyl/Capryl Glucoside and added 1% triethanolamine to raise the pH to ~8.5 to see if it would split. It didn’t.
I then took the three alternative surfactant experiments that were stable (Disodium Laureth Sulfosuccinate, Sodium Lauryl Sulfoacetate (and) Disodium Laureth Sulfosuccinate, Sodium C14-16 Olefin Sulfonate), portioned some off, and added ~1% of a fragrance oil rich in benzyl benzoate. All three were initially stable; it’s now been over two months and the experiment with Sodium Lauryl Sulfoacetate (and) Disodium Laureth Sulfosuccinate has split while the other two remain stable.
I adjusted the original formula to use Sodium C14-16 Olefin Sulfonate with the same active surfactant matter:
8.00% Glycerine
2.00% Hydroxyethylcellulose63.90% Distilled water
18.50% Sodium C14-16 Olefin Sulfonate
6.00% Cocamidopropyl Betaine
0.10% lake dyes (yellow + blue)0.50% Liquid germall plus
1.00% fragrance or essential oil
After making the base I divided the it in two and included 1% fragrance oil to one half and 1% essential oil blend to the other. Both fragrance blends contained benzyl benzoate and caused the Caprylyl/Capryl Glucoside version to split very quickly. Both versions very initially stable, but then split after about four days (vs ~20 minutes for theCaprylyl/Capryl Glucoside version).
So, what’s going on?
I still have no idea. There seems to be some sort of reaction happening between HEC, benzyl benzoate, and a couple surfactants… but then there also seem to be some reactions happening between just HEC and the surfactants. Here’s what I’ve learned:
- Basic non-ionic surfactants cause the body wash to split without any added fragrance
- An acidic non-ionic surfactant (Caprylyl/Capryl Glucoside) + benzyl benzoate causes splitting. No benzyl benzoate, no splitting.
- One basic anionic surfactant (Sodium Laureth Sulfate) caused splitting without any added fragrance
- Another basic anionic surfactant (Sodium C14-16 Olefin Sulfonate) is stable until benzyl benzoate is added
- Disodium Laureth Sulfosuccinate seems fine, while Sodium Lauryl Sulfoacetate (and) Disodium Laureth Sulfosuccinate splits (so the addition of the Sodium Lauryl Sulfoacetate is likely impacting the end product)
- pH seems like it might be a factor, but I haven’t been able to find any reliable link
That’s where I’m at. If you have any insights I would love to hear them!
Hello Marie,
I am soooooooo pleased you have discovered this anomoly as I too have been struggling and going demented trying to formulate a shampoo. I have tried all sorts but every time it curdled, my decision was to give up gums all together as they never seem to work for me, they either curdle or sink to the bottom after time. or fell too slimy. I think its surfactants which are picky with gums, I know that large manufacturers do use gums with success but there must be a science behind it which is beyond me! So now I am working on thickening in other ways using Cetyl alcohol and so on. Salt worked amazingly well but it cut my lather to ok rather than lush and creamy which is what I want to achieve, maybe just let salt we shall see, it goes on!!!!!
I’m glad it’s not just me! You should read the comment Pam left as well—it sounds like she is in the same place!
Thickening could be done with another surfactant `PEG-200 Hydrogenated Glyceryl Palmitate, PEG-7 Glyceryl Cocoate`. Its quick and easy, hope you can find it. Availability in Europe is good. I found it here under the name Rewoderm.
For the anionic solutions – have you tried thickening with salt?
There are different grades of HEC, each having different formulation requirements. I think the HEC is the troublemaker in your formulas. See if you can find out what grade HEC you have also and whether that grade will be compatible with surfactant systems. I believe lotioncrafter carries R-grade and I believe that grade HEC is better performing in surfactant systems. The Herbarie also carries HEC – but I’m not sure what grade.
If it were me, I would try experimenting with different thickeners. Surfactant systems are kind of picky. Different ones are going to require different thickeners. Sometimes they will thicken and be beautiful and no breaking – but will thin out over time to a watery consistency (still work fine, just the viscosity changes).
https://www.saveoncitric.com/hyalknashec.html <– this link gives a little tutorial on working with r-grade HEC. Maybe it will be helpful. Also do a google search for thickening surfactant systems with ethoxylated polymers. You should get some good information that way. I'm on my way to work or I would do some more research, but I wanted to give some feedback before I left today. I know we can figure this out! Good luck!
I’ll ask about the grade, thanks!
My preference for HEC is not only because of its gorgeous silky thickening but also for its lather boosting, which I have not found with other gums. I’m sure this would all work fine with Crothix, but I moreso want to know why this is happening rather than just avoid the things that I know trigger it 🙂
This won’t be helpful but add it to the mix. . .
I have purchased and scented liquid soap and made my own. When I scent the soaps they ALWAYS separate unless I add FO&EO Modifier that I purchase from Wholesale Supplies Plus.
I hope you figure this out and that your solution will help me so that I don’t have to use the modifier. Let me know if you would like to know the ingredients of the purchased or homemade soaps.
Thank you! More details would be very appreciated 🙂 I will look into the modifier as welL!
Purchased liquid soap ingredients:
Water, Ammonium Lauryl Sulfate, Ammonium Laureth Sulfate, Lauramide DEA, Lauryl Glucoside, Ammonium Xylene Sulfonate, Sodium Chloride, Citric Acid, Germaben Iie, Aloe Vera, Argan Oil, Coconut Oil, Avocado Oil, De-Ionized Water, FD&C Yellow #, D&C Red #, FD&C Blue #, D&C Violet #, D&C Green #, D&C Orange #
Homemade liquid soap ingredients:
Haha – I left the recipe at home. Will update when I remember. . .
Hi Marie,
I met you in London at the Formula Botanica conference and I, too, completed the diploma course. Right now, I’m in the midst of my final project for the hair course. I cannot tell you how excited I was to see this post as I have yet to make a shampoo with gums where what you describe didn’t happen. I have many, many bottles with awesome but water-thin shampoo in them and, at the bottom of the bottle, big globs of goo sit. I did not think about surfactants or essential oils as causal agents as I was convinced it was the thickener, so I did experiment with four different gums and could not locate a particular culprit. I was getting ready to try different thickeners including HEC and then siligel. Thanks to you, I’ll be approaching this dilemma differently. [I am determined to stay with natural/ ecocert products although it is tempting to just pull out my old bottle of crothix and call it a day…lol]Thank you for this fantastic post. Please keep us posted as you figure this out! -Pam BTW – gums I used include combinations of konjac, xantham, solagum, and sclerotium.
Thank you so much for sharing! I haven’t tried many other gums in body washes as I generally don’t like the consistency (I have tried xanthan and carageenan, but not enough to get deep enough to encounter this challenge). Have you tried making your shampoos without any kind of scent to see if that helps? I might also start choosing salt wherever possible. Hmm!
I am not as well versed as you but I noticed that Citric acid curdled my liquid soap when trying to adjust the PH. Perhaps one of the additives may have a similar make up and that is causing the issue.
Assuming your’e talking about true soap, the phenomenon you’re describing is different. Soap cannot be acidic, and adding enough acid to soap will cause it to cease to be soap. That’s what happened 🙂
Yeah that makes since and yes it was true soap. I did add too much citric acid as I tried again with a smaller sample and got the same. 🙂 Newbie mistake!
You won’t do it again, though! What a great way to learn 😀
I had the same issue even when using the essential oil blend in the recipe. Maybe the grade of HEC is the issue. It split after a couple of days. My only recipe flop so far!
How interesting—and sorry about that! You didn’t make any changes? Just the fir essential oil? Weeeeeeird. Hmmmm.
Nope no changes! It is like a science mystery. No need for sorry, I did it a few times to see if I goofed up on something.
How odd indeed! From the feedback/input I’m getting I would suspect the grade—I definitely need to do more digging into that angle. Hmmmmmmm.
Interesting. It actually explains why my schampoo (Betaine, Sodium Laureth Sulfate, guar gum as thickener) has curdled. It’s still usable though. I think I’ll have to experiment a lot with the recipe, unfortunately it’s measured in volumes and not in grams (I got it in my herbalism course).
Interesting! From the comments it sounds like this problem is not at all isolated to HEC. Hmmmmm. More experiments are in order!
Hi Marie,
Looking at your conclusions, the charge or lack thereof on the surfactant and /or pH seem to be the key factors. I don’t think the HEC is the problem necessarily.
Whenever you used an anionic surfactant (under basic conditions in most cases), then mixture was stable until benzyl benzoate was added. Anionic surfactants have a negatively charged hydrophilic end and are less effective at emulsifying oil-soluble and/or non-ionic components, such as benzyl benzoate.
Why the mixture split when SLS was used or when DLS was mixed with SLSa is a bit of a mystery though; pH and/or molecular size might be factors.
Whenever a basic non-ionic surfactant was used, the mixture split. Non-ionic surfactants have no charge on their hydrophilic end and are better at emulsifying oils than water-soluble components. If they are also a bit gel-like at room temperature, as some can be, when added to a gelling agent, it may increase this physical gelling attribute. Adding an amphoteric surfactant might help in this system.
In the case of the acidic non-ionic surfactant system that didn’t split, the acid increases the emulsifying capacity of the surfactant and the mixture is stable.
Whenever the component containing benzyl benzoate is present, the mixture splits. Benzyl benzoate is also more soluble in oil or alcohol than water. When added to your anionic surfactant system, the two are incompatible and the mixture splits.
If I’m faulty in my statements or conclusions, please correct me!
Sources:
https://cleanfax.com/carpet-care/anionic-nonionic-cationic-what-do-they-all-mean/
http://www.nenonatural.com/hair-blog/surfactants-explained-anionic-vs-non-ionic-vs-cationic-vs-amphoteric-als-vs-sls
http://www.thegoodscentscompany.com/data/rw1001672.html
Thanks for your thoughts! From my notes and recollections I think most of your conclusions are correct, except for the second one—anionic surfactants were hit-and-miss without the benzyl benzoate, regardless of pH.
I realize I’m late to the conversation, but I work with HEC often. I just made a face wash with 1% HEC, and I found it thick enough and completely smooth. I think the issue is in your using 2%. Anything above 1% usually results in a nasty, jelloid blob.
I have had beautifully smooth concoctions at 2% many times—as long as there’s no benzyl benzoate 🙂
I agree the % will only affect how viscous the product becomes, it won’t make or stop separation. Grade dear seem to be a factor and I think Leanne is most definitely onto something too. There is a lot of chemistry science going on in surfactant products which many of us DIYers are not familiar with. I agree that to have a foam booster is great but with a little tweaking on the surf blend and using salt as a viscosity modifier, this seems to work better……….so far!
Thank you so much for documenting all these details – that is quite a lot of work!
I have been experimenting with these types of ingredients also and have been using a 3 surfactant combination of Lauramidopropyl Betaine, Decyl Glucoside, and Caprylyl/Capryl Glucoside thickened with Xanthan. My tests have all different ratios of each of these three surfactants and while harshness varies, the gel behavior really does not. The Xanthan is always .7% of the total formula. I use Citric Acid to adjust the pH.
My oldest mixture is 5 days old and shows no signs of separation or thinning although there is some clumping – but it was there from the start and no amount of stirring gets rid of it using the usual hand mixer (no homogenizer available).
Astoundingly, the fragrance I used for all of them contains a ton of Benzyl Benzoate! Even though the clumpy mixtures seem to be stable in the first few days, I will see if it leads to separation later, but I am not getting that immediate splitting.
At the same time, I have been learning about gels and how they work (and don’t work) and it is quite a science, but from what I can tell, the gels are way picky. Tiny amounts of the wrong thing ruins the structure of the gel, releasing the water. Sounds like what you are seeing. So given the similarity of the surfactants we are both using with different results, it seems like it would be the thickener, to me. Unless the difference is the Lauramidopropyl Betaine vs Cocamodopropyl Betaine.
Not scientific, but another oddly shaped jigsaw puzzle piece.
Thanks for sharing! I’ve found hydroxyethylcellulose to be fairly unique in its fussiness in the realm of natural gums, but I love its skin feel and how it boosts lather so much that I keep playing with it to see where I can make it work 🙂
In my learning journey, I’m realizing that PH has A LOT to do with formulations “splitting”. In my case, i made a hyuralonic acid hand sanitizer and as originally made i got strings of snot in liquid. I was about to toss it and then thought, “hmmm, let me play with the PH”. I started adding tiny drops of citric acid and noticed immediately that the “strings of snot” LOL, started loosening and blending with the surrounding liquid. I then left it overnight and woke up to a beautiful homogenous, albeit HARD gel. I slowly added more alcohol and more calendula hydrosol until i got it the consistency I wanted and wallah! Beautiful hand sanitizer fortified with hyuralonic acid and calendula hydrosol with PLENTY of alcohol that stayed gelled. Now here’s the clincher – how on earth do i recreate? I’m sure you’ve experienced this- you save a bad recipe that you were ready to toss and went through so many ups and downs in your process in saving it that you forget what the heck you did. LOL
Hi. Marie. Do you have a list of essential oils and natural fragrance brands that DO NOT contain benzyl benzoate? Would love to know which to avoid when using HEC. Thanks!!
Definitely not; there are no brands that wouldn’t use benzyl benzoate, it’s on a product-by-product basis. Read this to learn how to check for yourself and you’ll quickly understand why I have not taken a week of my life to compile such a document 🙂
That said, it’s not as simple as hydroxyethylcellulose + benzyl benzoate = failure. Those two ingredients can play well in other types of formulations 🙂
Happy making!
Thanks! I’m a bit flummoxed right now because everything is splitting, of the 3 versions of my shampoo I tried with HEC and all different brands of natural fragrances. The SDS sheets didn’t mention benzyl benzoate at all, and the manufacturers confirmed that the fragrances didn’t contain any. All 3 contain half olefin sulfonate and half cocamidopropyl betaine as the surfactants. The same happens with guar gum in this formulation. Any ideas?
Gums + surfactants can be finicky; add in fragrances/essential oils and that just further complicates things. The hydroxyethylcellulose/benzyl benzoate thing really old seemed to hold steady with the exact surfactant blend I used, and was more varied with other surfactant blends, so don’t assume that it has to be benzyl benzoate. If the surfactant/gum blend is stable without fragrance, start looking at fragrant compounds that the failed versions have in common and go from there. Good luck + happy making!
I actually figured it out with step-by-step experimentation and narrowed down the problem to dispersing the HEC in glycerin! It does much better without that, and the HEC doesn’t even need the glycerin. Perhaps it’s the same situation for guar, which I’ll need to find out on some other occasion.
Interesting! And unexpected. Awesome work troubleshooting, hooray!
I’m also facing similar problem with the use of HEC at 0.5 %,0.8% and 1%. Different methods have been used to disperse and stir. I prepared it without the use of any EO and FO but yet always separating.
I’m guessing the surfactant system also have a role to play in separation. I’m working with SCI, caprylyl capryl glucoside, cocamidopropyl betaine and Sodium C14-C16 alpha olefin sulphonate.
Hi Malikah!
I’ve had no issues working with the combination you mentioned but I kept it to one primary surfactant (ie SCI or Sodium C14-16 Alpha Olefin Sulfonate) + the Caprylyl/Capryl Glucoside and Cocamidopropyl Betaine. I also added a co-emulsifer (superfatting agent)…Olivem300. For the SCI, I adjusted the PH to 6.2 – 6.7. According to my notes when I used the C14-16 Alpha Olefin I adjusted the PH between 5.3 – 5.8. It’s possible I adjusted PH so it wouldn’t separate but unfortunately I didn’t take great notes as to why I adjusted it lower than using SCI.. I also added the HEC/glycerin combination just before the preservative.
I used your base and the amounts you used, but I added another co-emulsifer (Olivem 300). I also added EDTA. I didn’t add any colour as I don’t have any lake dyes. I had no problems with separation. My method of mixing is below. You’ll notice that I added the glycerin and the HEC later in the process.
60.9 % distilled water (Phase A)
.20% Tetrasodium EDTA (Phase A)
18.5% Sodium C14-16 Alpha Olefin Sulfonate (40%) (Phase B)
6% Cocamidopropyl Betaine (30% surfactant) (Phase B)
3% Olivem 300 – as a superfatting agent/co-emulsifier (Phase C)
.7% essential oil (Phase C)
.2% Tocopherols – mixed (Phase C)
8% glycerin (Phase D)
2% Hydroxyethylcellulose (Phase D)
.5A% liquid germall plus (Phase E)
Method:
Combine phase A – mix low sheer until homogenous
Combine phase B – Add phase B to A – mix low sheer being careful not to add too much air/foam while you stir
Combine phase C – add phase C to A/B and stir slowly under low sheer.
Combine phase D. – Add to A/B/C and stir under low sheer.
Add Phase E to above and stir under low sheer.
Adjust PH to 5.3 – 5.8.
Thanks for sharing! Where is your hydroxyethylcellulose from?
Hey there Marie,
Just came across your post about curdling HEC.
Just to share, I have been formulating face washes with HEC for quite a while and too initially faced the mysterious curdling of HEC and even a total disintegration of HEC into a liquid form. What a disaster and I almost gave up on using HEC, despite HEC being the best thickener that is able to impact an elegant CLEAR face wash solution.
After what seems like an endless mix-and-match experiments with various surfactants, I realised that the “culprit” is actually CAPB aka cocamidopropyl betaine.
I used essentially a mixture of 3 surfactants, anionic + nonionic + amphoteric, all plant based. Somehow, CAPB needs to be added after the first 2 surfactants have been added. So how it goes is I blend the first 2 surfactants first (i.e. anionic + nonionic), then add in HEC Gel (which I made earlier). Stir gently to blend these 2 surfactants with the HEC Gel and let the solution rest for few hours.
After that, add in the CAPB and stir gently to combine. The HEC Gel will retain its viscous consistency via this method. If I were to blend the 3 surfactants together and then add in the HEC Gel immediately, it will quickly lose its viscosity and turn into a liquid state. As I’m not a chemist, I really do not understand how or why CAPB must be added separately and much later. I came across a post in a forum (I can’t remember which one) that shared the same finding as well. Chemistry can be so strange and mysterious LOL.
Also, another finding. DO NOT add citric acid at all into the formulation at the last stage. Doing so will turn CAPB into cationic which will attract the anionic surfactant and cause the entire blend to fail. With the plant based surfactants that I use, the pH is always around 5.5 which is the ideal state for skin care products.
So far, the face washes that I formulated with HEC give me a clear and beautiful texture. I have tried using both Xanthan and Sodium Alginate as the gum/thickener, but they can never impart that same clear texture as HEC.
Hope my findings can help shed some light on the mysterious curdling of HEC.
So I’ve been working for a LONG time on a cleansing shower cream. Basically a lotion with surfactants. At first I was using coco glucoside, cocamidopropyl betaine…Crothix as a thickener. Separated no matter what I did. Now I use SCI instead of coco glucoside, it doesn’t separate but the texture turns very clumpy and curdled looking after a day or two, probably because SCI isn’t water soluble. It’s like the SCI particles are fusing together? Still works fine when we can get it out of the bottle…
Now I’ve tried SLSA, and it separated after a week. I use a cold emulsifier and add it to hot water, blend in the SLSa, then add the cocamidopropyl betaine and that’s when it thins out immediately. It should be pretty thick with the emulsifier. I’m going to try to add the cocamidopropyl much later and see what happens!
Hi Ivan,
Please what anionic surfactant do you use?
I usually formulate my body cleansers with Sodium C14-16 olefin sulfonate (anionic), Decyl glucoside (non-ionic), and Cocamidopropul betaine (amphoteric), and my formulation always splits. I replaced the Sodium olefin sulfonate with Sodium laureth sulfate, and the same thing happened. And both the anionic surfactants have pH values above 8, so adjusting the formulations with citric acid is inevitable.
But surprisingly, my face cleansers which I formulate with a lot milder anionic surfactant, (Sodium lauroyl sarcosinate, or Apple amino acid), evening with pH adjustment do not split. Could it be because the ASM level of facial cleansers is lower than that of body cleansers requiring less amount when formulating? or is the type of surfactant? I haven’t tried them in body cleansers, as they are quite expensive compared to the former.
Would try your method, hopefully, it works.
Hi there. I really love your articles you are so inspiring. I made a bodywash but then it curdled so I added some nf in and the curdling went away now it just looks seperated. I think the nf worked so perhaps i should add more in. What do you suggest? Please thank you.