Help! Fatty Acids in Liquid Soap?

[MrsZ]

I would like to try to make liquid soap. I think I'm going to start with this recipe that has been recommended on here several times: Basic Beginner Liquid Soap and Information

I have found lots of recipes, and read about the methods. But I'd like to know more about formulating liquid soaps. I have a very basic idea of what the common fatty acids do in bar soap, but what qualities do the same fatty acids add to liquid soap?

For example, (and I know these are very basic generalizations, feel free to correct me. I have a lot to learn) Lauric and Myristic acids contribute higher cleansing properties to bar soap. Too high, and they can be very harsh on the skin. It seems from what I have read that this is true in LS as well.

It seems that oleic acid is the main one recommended for LS. Why is this? And ricinoleic seems popular too, for clarity in the finished product?

I've read that palmitic and stearic can cause cloudiness. I don't mind my soap being cloudy.

What I'd like is a somewhat gentle LS that I can dilute enough to use in a foamer. And while following recipes is great, I really want to know what makes the LS what it is. The information about fatty acids And what they contribute to bar soap is easy to find. I'm not sure how to translate all that to LS. And it bothers me to make something and not know why it works.

Would some of you knowledgeable people on here mind please pointing me in the right direction to learn more? Thanks in advance for taking the time to help me!

 

[DeeAnna]

If you don't mind a potentially cloudy soap, you can adapt any recipe you use to make regular bar soap. Obviously the hardness and longevity numbers don't apply to LS.

When I first started out, I followed the Irish Lass / 3Bees recipe you mentioned. I did that because I wanted to learn to make LS with a tried and true recipe. And it is fun to have at least one recipe that makes a crystal clear LS.

But I don't think formulating LS recipes has to be mysterious or difficult. There are a couple of things to think about in addition to what you'd do to design a bar soap recipe, but it's not all that complicated.

One goal I have is to keep the oleic acid content somewhere around 50% to 60%. I know from experience this range of oleic acid will will give me a nicely thick soap when it's diluted with a reasonable amount of water.

If the oleic is a lot higher, the LS requires a lot of water to dilute, so the diluted soap might be very low in soap content, which means it won't lather or clean as well. If the oleic is low, you can't get a nicely thick soap, if that's what you want.

I'm pretty sure a higher % of palmitic and stearic acids also contributes to thickness, so they can offset a lower oleic acid content. These fatty acids aren't as popular in LS because the tend to make the soap cloudy or opaque, however, but that's not an issue for me.

I've made LS with 80% lard + 15% coconut + 5% castor. That combination lathered nicely and was quite thick, but it tended to separate into a thin white layer floating on the main portion of slightly milky soap. I know stearic soap molecules don't want to stay dissolved in water very well, so I imagine that's why this soap tends to separate slightly.

A secondary goal I keep in mind is I want to keep the the lauric + myristic acid content in a range that won't be overly drying to my skin. LS recipes often have high percentages of coconut oil and I'm guessing that's to boost the lather. But I find my LS lathers well enough with moderate amounts of coconut, which is fine by me.

 

[MrsZ]

If you don't mind a potentially cloudy soap, you can adapt any recipe you use to make regular bar soap. Obviously the hardness and longevity numbers don't apply to LS.

When I first started out, I followed the Irish Lass / 3Bees recipe you mentioned. I did that because I wanted to learn to make LS with a tried and true recipe. And it is fun to have at least one recipe that makes a crystal clear LS.

But I don't think formulating LS recipes has to be mysterious or difficult. There are a couple of things to think about in addition to what you'd do to design a bar soap recipe, but it's not all that complicated.

One goal I have is to keep the oleic acid content somewhere around 50% to 60%. I know from experience this range of oleic acid will will give me a nicely thick soap when it's diluted with a reasonable amount of water.

If the oleic is a lot higher, the LS requires a lot of water to dilute, so the diluted soap might be very low in soap content, which means it won't lather or clean as well. If the oleic is low, you can't get a nicely thick soap, if that's what you want.

I'm pretty sure a higher % of palmitic and stearic acids also contributes to thickness, so they can offset a lower oleic acid content. These fatty acids aren't as popular in LS because the tend to make the soap cloudy or opaque, however, but that's not an issue for me.

I've made LS with 80% lard + 15% coconut + 5% castor. That combination lathered nicely and was quite thick, but it tended to separate into a thin white layer floating on the main portion of slightly milky soap. I know stearic soap molecules don't want to stay dissolved in water very well, so I imagine that's why this soap tends to separate slightly.

A secondary goal I keep in mind is I want to keep the the lauric + myristic acid content in a range that won't be overly drying to my skin. LS recipes often have high percentages of coconut oil and I'm guessing that's to boost the lather. But I find my LS lathers well enough with moderate amounts of coconut, which is fine by me.

Thank you, @DeeAnna . I really appreciate you taking the time to write such a detailed reply. I feel a little more confident to attempt making LS now. What do you know about ricinoleic acid in LS? Is it necessary? Does castor oil help stabilize lather in LS as well? Thank you again for your help.

 

[DeeAnna]

I don't have a strong opinion about castor. I've made LS with and without castor. I can't say I see a huge difference, but that's just an informal observation. Others may feel differently about that.

I do know castor increases the water solubility of soap. That might be a useful property for bar soap, but I'm not sure how critical that property is for LS.

The common wisdom in the handcrafted soap making world is that castor also adds to the clarity of liquid soap. I haven't researched or done any experiments to know if this idea is really true or if it's one of those "everyone thinks it's true so therefore it must be true" ideas.

 

[MrsZ]

I don't have a strong opinion about castor. I've made LS with and without castor. I can't say I see a huge difference, but that's just an informal observation. Others may feel differently about that.

I do know castor increases the water solubility of soap. That might be a useful property for bar soap, but I'm not sure how critical that property is for LS.

The common wisdom in the handcrafted soap making world is that castor also adds to the clarity of liquid soap. I haven't researched or done any experiments to know if this idea is really true or if it's one of those "everyone thinks it's true so therefore it must be true" ideas.

That makes sense, thank you. I think you have given me enough to go by for the moment, and I'm sure I will be asking more questions once I start making LS. I feel ready to give LS a try now that I have at least some idea of what to expect from the FA's. Thanks again for your help!

 

[Zany_in_CO]

But I'd like to know more about formulating liquid soaps.

There are a LOT of Liquid Soap recipes around. Most of them are large batches. No matter what recipe you try, start with small batches. Resize the batch to 12 oz oils = 16 oz. paste. You can then divide that up into four 4 oz. portions to play with to determine the optimum amount of dilution water, colorant, fragrance, etc. needed.



When using SoapCalc, be sure to choose "KOH". Seems obvious, but it's easy to forget.
Under the "Water" heading, choose Water : Lye Ratio and type in 3:1. 

For Super Fat, I choose 0% because I want all my fats/oils fully saponified. Some LS'ers use 3-4% SF which is a matter of preference. It eliminates the need to neutralize excess lye.

Leave Fragrance blank until after the batch is diluted. Here's how it looks.

Formulating LS is about more than the choice of fatty acids. Equally important is the amount of dilution water used. While it's true that you can dilute to your personal preference, i.e., more soap than water, you may find that you're rinsing longer, i.e., washing excess soap down the drain, rather than having a "perfect measure" that rinses clean quickly. The info in this thread explains the process in greater detail.

Too high, and they can be very harsh on the skin. It seems from what I have read that this is true in LS as well.

Not true. For example, I make 100% Coconut Oil LS for laundry. I sometimes use it in foamers. At 0% SF It is crystal clear, and not drying at all. Coconut is the Mainstay of LS because LS that contains 50% or more coconut can be diluted at 40% soap to 60% water vs 100% olive oil that should be diluted at 15% soap to 85% water. However, this results in lovely lather that rinses clean but has a watery texture that needs to be thickened with salt (brine). Read more:

WHAT TO EXPECT FROM VARIOUS OILS IN LS

And while following recipes is great, I really want to know what makes the LS what it is.

While a lot has changed since Catherine Failor published the "Bible" of making LS in 2000, the basic information provided still applies, although her method is pretty much passe´. You can probably borrow it from your local library or find it online.

MAKING NATURAL LIQUID SOAPS

Another thing I should mention is whether you HP or CP your LS.
Newbies often run into trouble when they can't tell whether or not their batch has cooked long enough (HP). Bring the soap to hard trace and stopping there (CP) is similar to making hard bars in that, rather than cooking the batch, you cover it and allow it to finish saponification over time, usually 2 weeks (depending on choice of oils.) Read this thread for more info.

 

[MrsZ]

There are a LOT of Liquid Soap recipes around. Most of them are large batches. No matter what recipe you try, start with small batches. Resize the batch to 12 oz oils = 16 oz. paste. You can then divide that up into four 4 oz. portions to play with to determine the optimum amount of dilution water, colorant, fragrance, etc. needed.



When using SoapCalc, be sure to choose "KOH". Seems obvious, but it's easy to forget.
Under the "Water" heading, choose Water : Lye Ratio and type in 3:1. 

For Super Fat, I choose 0% because I want all my fats/oils fully saponified. Some LS'ers use 3-4% SF which is a matter of preference. It eliminates the need to neutralize excess lye.

Leave Fragrance blank until after the batch is diluted. Here's how it looks.

View attachment 59898
Formulating LS is about more than the choice of fatty acids. Equally important is the amount of dilution water used. While it's true that you can dilute to your personal preference, i.e., more soap than water, you may find that you're rinsing longer, i.e., washing excess soap down the drain, rather than having a "perfect measure" that rinses clean quickly. The info in this thread explains the process in greater detail.

Not true. For example, I make 100% Coconut Oil LS for laundry. I sometimes use it in foamers. At 0% SF It is crystal clear, and not drying at all. Coconut is the Mainstay of LS because LS that contains 50% or more coconut can be diluted at 40% soap to 60% water vs 100% olive oil that should be diluted at 15% soap to 85% water. However, this results in lovely lather that rinses clean but has a watery texture that needs to be thickened with salt (brine). Read more:

WHAT TO EXPECT FROM VARIOUS OILS IN LS


While a lot has changed since Catherine Failor published the "Bible" of making LS in 2000, the basic information provided still applies, although her method is pretty much passe´. You can probably borrow it from your local library or find it online.

MAKING NATURAL LIQUID SOAPS

Another thing I should mention is whether you HP or CP your LS. Newbies often run into trouble when they can't tell whether or not their batch has cooked long enough (HP).
Read this thread for more info.

Thanks for all of your advice and resources! I will read all the links you provided.

 

[Tara_H]

Thanks for all of your advice and resources! I will read all the links you provided.

Oh, and if you're resizing LS recipes, be very conscious that they may behave differently while making. The times, consistencies etc may be radically different from described. Especially for HP, where in a small quantity it's easy to lose a high percentage of the water to evaporation.

 

[MrsZ]

Oh, and if you're resizing LS recipes, be very conscious that they may behave differently while making. The times, consistencies etc may be radically different from described. Especially for HP, where in a small quantity it's easy to lose a high percentage of the water to evaporation.

Thanks for the tip! I wouldn't have thought of that.

 

[MrsZ]

While a lot has changed since Catherine Failor published the "Bible" of making LS in 2000, the basic information provided still applies, although her method is pretty much passe´. You can probably borrow it from your local library or find it online.

MAKING NATURAL LIQUID SOAPS

Thank you, @Zany_in_CO , for the book recommendation. I bought this book on Kindle and have been reading it. She makes the chemistry behind soapmaking sound so simple!

 

[AliOop]

You might also consider Ultimate Guide to Liquid Soap. It's a $45 instant download, and you can often find discount codes on her open FB group, especially around holidays (so look for one around Labor Day). She provides a thorough scientific background, in-depth information regarding fatty acids in LS, and detailed instructions for the different methods of liquid soap-making. I found it much easier to follow than the Failor book - but everyone has her own learning style, so YMMV.

 

[MrsZ]

You might also consider Ultimate Guide to Liquid Soap. It's a $45 instant download, and you can often find discount codes on her open FB group, especially around holidays (so look for one around Labor Day). She provides a thorough scientific background, in-depth information regarding fatty acids in LS, and detailed instructions for the different methods of liquid soap-making. I found it much easier to follow than the Failor book - but everyone has her own learning style, so YMMV.

Oh, that sounds amazing! Thank you! I will keep that in mind for another paycheck. What is her FB group?

 

[ResolvableOwl]

What I'd like is a somewhat gentle LS that I can dilute enough to use in a foamer.

If you have one or two days more patience – I'm about to update my LS construction kit thread anyway, and it will address several of your questions (that are my questions as well)!

One foamer-related bit of information beforehand: We tend to think of LS as water + soap, but it really is water + soap + glycerol. And as it turns out, glycerol, while improving viscosity and giving a gentle skin feel, can diminish lather in some weird way that impedes the effect of foamers. @IrishLass's GLS, for example (in a variation without coconut oil), gave me terrible foamer experience.
One point about potassium palmitate and stearate is that they won't contribute to foamer lather as long they are precipitated in the working solution (LS turbid when diluted for foamer use) – they will, but not until you distribute them on the skin. Complicated thingies, these foamers, and I can't wait for my dilution series to shed some light on all these confusing interconnections.

 

[MrsZ]

If you have one or two days more patience – I'm about to update my LS construction kit thread anyway, and it will address several of your questions (that are my questions as well)!

One foamer-related bit of information beforehand: We tend to think of LS as water + soap, but it really is water + soap + glycerol. And as it turns out, glycerol, while improving viscosity and giving a gentle skin feel, can diminish lather in some weird way that impedes the effect of foamers. @IrishLass's GLS, for example (in a variation without coconut oil), gave me terrible foamer experience.
One point about potassium palmitate and stearate is that they won't contribute to foamer lather as long they are precipitated in the working solution (LS turbid when diluted for foamer use) – they will, but not until you distribute them on the skin. Complicated thingies, these foamers, and I can't wait for my dilution series to shed some light on all these confusing interconnections.

So may things to think of! I am definitely going to wait a bit before I make the soap. I will read your thread update as well before I give it a try.

 

[Zany_in_CO]

We tend to think of LS as water + soap, but it really is water + soap + glycerol. And as it turns out, glycerol, while improving viscosity and giving a gentle skin feel, can diminish lather in some weird way that impedes the effect of foamers. @IrishLass's GLS, for example (in a variation without coconut oil), gave me terrible foamer experience.

Interesting! My experience coincides with that statement so I'm glad to see it validated by your experience. That's why the only LS I make with glycerin is Olive Oil Castile using Carrie's Glycerin LS -- the method that got the whole glycerin-sub-for-water to make the lye solution going.

100% Olive Oil LS (and similar) is the slowest of all oils to trace and takes forever to cook. With Carrie's method, the soap really does trace in all of 2 minutes right before your eyes. (FUN!) A huge time-saver for me. NOT for beginners, though, due to the high heat of the KOH solution and possibility of toxic fumes if the solution is overheated. (TIP: Remove from heat source the second you see heat waves rising from the surface. )

 

[Zany_in_CO]

I found it much easier to follow than the Failor book

Yes. It is confusing and poorly organised, IMO. BUT. The basic info is solid and I refer to it often when I or someone on SMF encounters a problem. When I think about it, imagine being the first person who waded into LS territory all by her lonesome. What an amazing accomplishment that brought so much joy to the soapmaking community! A lot has changed in the 21 years since it was first published. I would love to get a peek at Ashley Green's "Ultimate Guide" but I'm not about to pay $45 for the privilege. Failor's book can be found in most libraries and online at Thrift Books, among others.

 

[AliOop]

Oh, that sounds amazing! Thank you! I will keep that in mind for another paycheck. What is her FB group?

Sorry, I'm not on FB anymore, but I think it was called Ultimate Soap or something like that.

 

[ResolvableOwl]

So may things to think of! I am definitely going to wait a bit before I make the soap. I will read your thread update as well before I give it a try.

https://www.soapmakingforum.com/threads/tracing-saponification-speed-test.84685/post-905005tl;dr: If you're aiming at foamers, life is much easier than regular LS dispensers. Many FA profiles (mostly-oleic as a notable exception) give decent foam. Lauric oils are huge for foamers, but already do their fabulous work at very low concentrations, so no reason to crank up CO.

 

[MrsZ]

https://www.soapmakingforum.com/threads/tracing-saponification-speed-test.84685/post-905005tl;dr: If you're aiming at foamers, life is much easier than regular LS dispensers. Many FA profiles (mostly-oleic as a notable exception) give decent foam. Lauric oils are huge for foamers, but already do their fabulous work at very low concentrations, so no reason to crank up CO.

That's good to know, thank you.

 

[Susie]

Interesting! My experience coincides with that statement so I'm glad to see it validated by your experience. That's why the only LS I make with glycerin is Olive Oil Castile using Carrie's Glycerin LS -- the method that got the whole glycerin-sub-for-water to make the lye solution going.

100% Olive Oil LS (and similar) is the slowest of all oils to trace and takes forever to cook. With Carrie's method, the soap really does trace in all of 2 minutes right before your eyes. (FUN!) A huge time-saver for me. NOT for beginners, though, due to the high heat of the KOH solution and possibility of toxic fumes if the solution is overheated. (TIP: Remove from heat source the second you see heat waves rising from the surface. )

There is always the "dilute the KOH with water then add the glycerin to the oils" way around that method as has been explained many times. Simply substitute equal weight of KOH with water rather than glycerin. No need to fret about heating up glycerin and KOH. Then, once diluted, simply add the remainder of the glycerin weight as glycerin to the oils. It makes no difference to the outcome of the soap. It still makes a gloriously thick liquid soap that dilutes well and foams beautifully.