Are Lauric and Myristic acids still drying in liquid soap?

[Sri Astuti]

Hello all. This is my first post here after lurking silently for so long. I have just read the book 'The Ultimate Guide to Liquid Soap", and I think I found one statement in the book that said that Coconut oil with its lauric and myristic acids behave differently in liquid soaps. It is not drying like in a bar of soap, as they help the soap to be more soluble in water. And I am confused. I don't think it is true. Those fatty acids will still dry our skin both in liquid soap as well as in solid bar of soap. But I am trully not experienced much yet in liquid soap. Thus, this post. I make bar soaps and usually only use maximum 20% of Coconut oil. Even that, I still find it drying. In you experience, how much coconut oil should we use in a liquid soap recipe so that it is gentle enough for our skin? Thank you so much for sharing your expertise, knowledge, experience and wisdom.

 

[AliOop]

Hi there! So glad you are no longer just lurking.

I personally find that coconut oil isn't quite as stripping in LS, but only to a point. I also keep my bar soaps to a max of 20% CO. In LS, I have gone as high as 48% and not had it be drying. I initially make it with 0% SF, and then add 2-3% SF (with an equal amount of PS80) during dilution. I should also mention that I heavily dilute my paste so the LS can be used on foamer bottles. That's important to me, because I don't end up with as much concentrated soap on my hands. That makes it less drying, plus we don't go through it as fast.

HTH!

 

[Benjamin]

I am sure someone will be able to offer a more scientific answer, but I am happy to share my practical experience. I’ve been experimenting recently with 100% coconut oil soap for household cleaning. It works very well for cleaning, but I find it very stripping on my hands.

In contrast, I use 14% palm kernel oil for liquid hand soap and don’t find it drying at all.

So, for me, for both liquid and bar hand and body soaps, I like to keep lauric and myristic acids pretty low.

I do find that oleic acid behaves differently in KOH. I can go much higher on the oleic acid content in KOH soap without getting any “snotty” feeling like I do in NaOH bar soap.

Hope this helps!

 

[Sri Astuti]

Hi there! So glad you are no longer just lurking.

I personally find that coconut oil isn't quite as stripping in LS, but only to a point. I also keep my bar soaps to a max of 20% CO. In LS, I have gone as high as 48% and not had it be drying. I initially make it with 0% SF, and then add 2-3% SF (with an equal amount of PS80) during dilution. I should also mention that I heavily dilute my paste so the LS can be used on foamer bottles. That's important to me, because I don't end up with as much concentrated soap on my hands. That makes it less drying, plus we don't go through it as fast.

HTH!

hahaha thank you for the welcome, AliOop. And thank you for explaining it to me.

I am not used to writing in this kind of forum, it took so long to summon my courage to ask a question. But I enjoy reading all posts and that's what I've been doing for 1 and a half year before this first question. Even typing this response took me so long with me wondering where things were. I wanted to insert an emoji and don't know where they are hahahah

I am planning to use the same amount of Coconut oil (20%) in my liquid soaps and see if I like the suds. What is PS80, if I may ask?

I am sure someone will be able to offer a more scientific answer, but I am happy to share my practical experience. I’ve been experimenting recently with 100% coconut oil soap for household cleaning. It works very well for cleaning, but I find it very stripping on my hands.

In contrast, I use 14% palm kernel oil for liquid hand soap and don’t find it drying at all.

So, for me, for both liquid and bar hand and body soaps, I like to keep lauric and myristic acids pretty low.

I do find that oleic acid behaves differently in KOH. I can go much higher on the oleic acid content in KOH soap without getting any “snotty” feeling like I do in NaOH bar soap.

Hope this helps!

Thank you Benjamin for taking the time to help a newbie out. PKO is similar as Coconut oil, right? So in your liquid soaps you only use PKO up to 14%? Does it make good lather?

My soap bars range between 10-20% of Coconut oil. I am thinkng of going to use the upper end of that range for my liquid soap to ensure good lather.

 

[Benjamin]

Hi @Sri Astuti, yes PKO is used similarly to coconut oil. I find it slightly less stripping than coconut oil. It could be completely psychosomatic. As I’ve gotten older I prefer lower amounts of CO/PKO. When I started soaping I liked around 25%. Now I find that too harsh. I find I get more than enough bubbles at 14% and my skin is happier.

 

[DeeAnna]

The soap recipe c@lculators I'm aware of only track the main fatty acids found in soap -- lauric, myristic, palmitic, stearic, oleic, linoleic, linolenic, and ricinoleic. If a fat contains significant amounts of fatty acids not tracked by the calc you're using, you'll never know about these "invisible" fatty acids if you simply take the calc results at face value.

For example, the fatty acid profiles for palm kernel oil (PKO) and coconut oil (CO) appear to be about the same in many soap calcs. But there are two "invisible" fatty acids present in these two fats -- capric and caprylic acids.

PKO tends to have lower amounts of capric and caprylic acids. Combined with lauric acid, they will increase the harshness of soap made from CO or PKO. According to my notes, here are typical percentages of the "cleansing" fatty acids in these two fats:

Coconut oil:
Caprylic 8%
Capric 7.5%
Lauric 46%
Myristic 19%

Palm kernel oil:
Caprylic 4%
Capric 4%
Lauric 48%
Myristic 16%

PKO has roughly half the amount of caprylic and capric acids that coconut has. That's very likely the reason why PKO might legitimately be a bit milder to the skin. There could also be some placebo effect going on too, because the lauric acid content in PKO and CO are roughly the same.

Digression: There are other invisible fatty acids. For example, butyric acid, found in dairy milk, isn't tracked by the calcs and it too adds harshness to soap as well as a strong objectionable odor many people don't care for. A tiny amount of butyric in fluid cow's milk isn't enough to increase harshness or add significant odor. But if one makes soap using butter or heavy cream, the larger dose of butyric can be a problem.

edit: And another fat -- fractionated coconut oil (FCO) also called medium chain tryglycerides -- is almost entirely capric and caprylic acids with very little lauric acid and no myristic acid. FCO is nice used as-is for skin and hair care, but makes a very harsh soap. It seems to be a trendy ingredient for new soap makers to use rather than regular coconut, but I sure hope that trend dies out soon.

 

[AliOop]

I am planning to use the same amount of Coconut oil (20%) in my liquid soaps and see if I like the suds. What is PS80, if I may ask?

PS80 is an abbreviation for Polysorbate 80. It is a commonly used solubilizer that allows you to add fragrance and superfat to liquid soap, without the typical separation you would otherwise experience. Very handy stuff!

Based on what DeeAnna and Benjamin wrote above, it might be worth trying PKO, and at a lower rate than 20%. I’ll probably try that on my next batch, too.

 

[Benjamin]

@DeeAnna, I was going to reference your posts about capric and caprylic acids, but you did it for me. I think I first read about it in an old thread with you and Zany.

FWIW I started by decreasing the coconut oil, and then by mixing PKO and coconut oil. I systematically decreased the coconut until it stopped bothering me. I got down to 6% coconut and 6% PKO. At that point I wondered if the coconut was even worth it. I dropped the coconut, and worked my way back up to 14% PKO. That seems to be the sweet spot for me.

 

[Sri Astuti]

woooww ... thank you so much, people. You are all so generous with your knowledge and time to write a response here. I am continually amazed at the amount of support and quality of information members can get in this forum.

Upon reading @DeeAnna's suggestion about PKO, I started looking for it in the marketpalce in my country, and I am just amused that I could only find ONE seller in the whole country, and it is from a different island far away from where I live so will take almost a week to ship it to me. I am from Indonesia, and Palm oil and Coconut oil are staples in our diet. We use them daily to cook. But when it comes to PKO, it is so rare. What do we do with it? Do we export it all to other countries?

But I am going to get some PKO from this only seller. Worth trying.

I tried the other day making a liquid soap with this recipe:
- Coconut oil 18%
- Sunflower oil (not high oleic) 12%
- Palm oil 8%
- Castor oil 14%
- Olive oil 48%

Supertfat 2%. Liquid:lye ratio 3:1 with half of it using glycerine.

I used cold process. Today (after 48 hours) I tried diluting it, it's still cloudy. And I can feel some dryness at the palms of my hand. Will liquid soap get gentler with age too just like solid soaps?

And the cloudiness, is it because of the cold process (no cooking at all) I used? Will it clear up right away if I use hot process?

Thank you so much for everyone's response. I appreciate it. Xo xo

 

[AliOop]

I do find that LS gets milder with time. Some makers do recommending "sequestering" your diluted soap, which means setting it aside for a week or two after diluting and before using. I liken it to how Italian food, or most any soup, tastes better the next day, after all the ingredients become good friends while in the fridge together overnight.

Cloudiness typically has to do with ingredients, including certain fatty acids and fragrances. It can also be from unsaponified oils, in this case, your superfat. If I go over 1% SF with my most typical recipe, or if I use high-stearic ingredients (lard, tallow, stearic acid), the diluted soap definitely clouds up. It is most often a cosmetic issue that doesn't affect the soap quality. You can trying diluting it a bit further, or adding a a few drops of a KOH solution to saponify some of the SF. You can also let it sit for a few days to see if it clears up on its own.

 

[Servant4Christ]

The soap recipe c@lculators I'm aware of only track the main fatty acids found in soap -- lauric, myristic, palmitic, stearic, oleic, linoleic, linolenic, and ricinoleic. If a fat contains significant amounts of fatty acids not tracked by the calc you're using, you'll never know about these "invisible" fatty acids if you simply take the calc results at face value.

For example, the fatty acid profiles for palm kernel oil (PKO) and coconut oil (CO) appear to be about the same in many soap calcs. But there are two "invisible" fatty acids present in these two fats -- capric and caprylic acids.

PKO tends to have lower amounts of capric and caprylic acids. Combined with lauric acid, they will increase the harshness of soap made from CO or PKO. According to my notes, here are typical percentages of the "cleansing" fatty acids in these two fats:

Coconut oil:
Caprylic 8%
Capric 7.5%
Lauric 46%
Myristic 19%

Palm kernel oil:
Caprylic 4%
Capric 4%
Lauric 48%
Myristic 16%

PKO has roughly half the amount of caprylic and capric acids that coconut has. That's very likely the reason why PKO might legitimately be a bit milder to the skin. There could also be some placebo effect going on too, because the lauric acid content in PKO and CO are roughly the same.

Digression: There are other invisible fatty acids. For example, butyric acid, found in dairy milk, isn't tracked by the calcs and it too adds harshness to soap as well as a strong objectionable odor many people don't care for. A tiny amount of butyric in fluid cow's milk isn't enough to increase harshness or add significant odor. But if one makes soap using butter or heavy cream, the larger dose of butyric can be a problem.

edit: And another fat -- fractionated coconut oil (FCO) also called medium chain tryglycerides -- is almost entirely capric and caprylic acids with very little lauric acid and no myristic acid. FCO is nice used as-is for skin and hair care, but makes a very harsh soap. It seems to be a trendy ingredient for new soap makers to use rather than regular coconut, but I sure hope that trend dies out soon.

Thank you so much for all this invaluable information. I think you just convinced me to order some PKO.

 

[Sri Astuti]

PS80 is an abbreviation for Polysorbate 80. It is a commonly used solubilizer that allows you to add fragrance and superfat to liquid soap, without the typical separation you would otherwise experience. Very handy stuff!

Based on what DeeAnna and Benjamin wrote above, it might be worth trying PKO, and at a lower rate than 20%. I’ll probably try that on my next batch, too.

If it can emulsify superfat with the liquid soap, this is my layman brain thinking, then can PS 80 be used to emulsify the unsaponified oils back into the soap so they don't separate and cloud the soap? Am I right to think this @AliOop and @DeeAnna ? Because if it can, then it can replace the use of adding some KOH solution into soap to saponify what is left unsaponified. It will be safer that way, right? Or not?

 

[Sri Astuti]

BTW. @DeeAnna, I finally gathered my courage to try adding dry KOH flakes to my liquid soap that has very bad separation (photo 1). This is a Castile soap (100% Olive Pomace Oil) using 2% superfat. Cold Process. I used my fragrance oil scale so it can measure small increments in weight, and added 1% of the total weight of soap with dry KOH. Then I gave it a shake well. It got really thick and become a big sticky blob, so I added a little water, then let it settle overnight. And lo and behold, the next day, it clears up really beautifully. (photo 2).

However, I am scared of trying it. What if now it is lye heavy instead? How can I test it safely?

Will KOH react also with CO2 like NaOH and become neutralized after a while? How can I make sure the soap is safe to use after adding KOH (both dry or solution)?

Now, another question, on clarity of liquid soaps.

Another thing that also bugs me about the book I mention above is that, the author has a recipe with 20% Cocoa butter that turned out clear. She used high temperature and some cooking time. I tried the same recipe with CP, and it did not want to clear at all. So I am wondering if cooking the soap (the method used to make the soap, whether CP or HP) can really make a difference in clarity.

Thank you so much for your always knowledgeable inputs, @DeeAnna, @AliOop and all other members of this amazing forum.

 

[AliOop]

Oh goodness. My previous suggestion was to add a KOH solution, that is, KOH that has been dissolved in water. Normally that is added a few drops at a time until the soap clears. Next time, try that instead of adding dry KOH flakes. Thankfully you did add more water, so hopefully that dissolved all of it. At this point, you can try zap-testing your soap to see if it is lye-heavy.

PS80 can help keep unsaponified oils (from your superfat) mixed with the diluted soap, but it doesn't normally help with clarity. In fact, I typically experience the opposite - the soap is less clear after I add PS80.

But I must admit, I don't understand the focus on achieving perfectly clear soap. Clarity alone doesn't equal good soap. My goal is to have a soap that isn't drying to my hands. Sometimes that means my soap won't be clear, because I've added PS80, some superfat, and some fragrance, or I've use a fat that doesn't produce clear soap. I don't really understand why that's a problem for anyone.

 

[Sri Astuti]

Oh goodness. My previous suggestion was to add a KOH solution, that is, KOH that has been dissolved in water. Normally that is added a few drops at a time until the soap clears. Next time, try that instead of adding dry KOH flakes. Thankfully you did add more water, so hopefully that dissolved all of it. At this point, you can try zap-testing your soap to see if it is lye-heavy.

Thank you for your prompt response, @AliOop.

Yes, you did recommend adding KOH solution. But I've read somewhere, I think in one of @DeeAnna responses, forgive me if I am mistaken, DeeAnna, that we can actually add dry KOH as there is already enough liquid in the liquid soap to dissolve the KOH. I actually find it easier with dry flakes, as it is more straight forward in weighing it. Please let me know if I did it right, otherwise, I am doomed.

I did try zap test. With soap already diluted, I just get a little bit of it in my fingers, work it until sudsy, and just test it to the tip of my tongue, correct? It's not zappy. But to be honest, I did not exactly know how zappy feels like. It just tasted like soap, and rather sweet. :\

 

[Sri Astuti]

Does zappy feeling feel like your tongue being scalded by very hot coffee? No, not this castile liquid soap that I added dry KOH to, but another soap I tested a long time ago. I can still feel the scalding sensation whenever I conjure up the memory. Is that the correct comparison of a zappy feeling I am looking for whevener I do a zap test?

 

[AliOop]

If DeeAnna said you can do it the way you did it, then that's good enough for me.

A zap will feel like an immediate electric shock - quite unpleasant, and perhaps that could be akin to a scalding? In any event, the sensation will be strong and immediate - not delayed, not building over time, and not really related to the taste of the soap at all. Since it sounds like your soap is just soapy and sweet, it seems that all is well for this batch. Hooray!

 

[DeeAnna]

I won't necessarily share this directly to someone who is fairly clueless and impatient, but, yes, I will add dry KOH to DILUTED liquid soap. There's already a lot of water in diluted soap, so I know there's plenty of water available to dissolve the KOH. Stir well just as if you were adding a solution of KOH and water, and you'll find the KOH dissolves quickly and completely.

Whether adding a solution or adding the dry alkali to correct for excess fat or fatty acid, you have to be patient with the process. Give the KOH time to fully react and bear in mind that a little KOH can go a long way to consume a fatty excess. Don't get in a hurry.

Another thing to keep in mind when adding KOH to liquid soap is the resulting zap test could potentially be ... exciting ... so test with extreme care. Only a tiny invisible smear of soap on a finger tip and just a small, light touch of said fingertip to the tongue. Spit (don't swallow!) and rinse well with cool water.

Like Ali said, if the soap is lye heavy, even a little bit, the sensation from a zap test is immediate and unmistakable. If you are wondering "is it or isn't it?", then it's not a zap.

I know people want to believe a pH test is a substitute for a zap test, but it's not. Soap will be unsafe for use on the skin even if the soap has only a tiny bit of excess lye. A pH test, even using the best of pH test strips, is not remotely sensitive enough to show the difference.

 

[Sri Astuti]

hooraaaay .. OMG I am so happy. I had made liquid soaps before that ended up separated badly. I used the clear part at the bottom and chucked the rest of it as I did not know what to do about it. I did not know what caused it either. That's why I then stopped making liquid soap for quite a long time. I got "traumatized" by the waste of expensive oils due to not knowing any better. I am better equipped with the knowledge now to start again. I am so happy. Thank you everyone. Thank you so much for all your amazing advice.

 

[Sri Astuti]

Dear all, this is an update. I finally got my PKO, and made my liquid soap using the same recipe in post #9. I just changed the coconut oil with PKO. It turned out very clear, and I think I can feel it is better, a bit gentler, than the one with the same amount of Coconut oil. With 18% coconut oil in LS, I have to apply hand lotion after washing my hand. With PKO, I find it is not necessary. But I will definitely lower this number, both for PKO and Coconut oil. 18% turns out to be still a little too high for me.

I have a question, @DeeAnna. If the shorter chain fatty acids contribute to the more aggresive cleansing action, why are they not considered in any soapmaking calculator? And what is it that causes this ability to remove oils so effectively in these short(er) fatty acids? Does their carbon tail length or structure influence this ability?

Thank you so much for your insight.