by "the numbers" (soapcalc, butters, and single-oil soaps)

[JBot]

It seems pretty well-documented that soapcalc's numbers don't always tell the whole story and that there are exceptions to its "rules." 100% olive oil soap is an often-cited example. But there are other things about "the numbers" that are plaguing me.

Tallow and lard are both considered reasonable for single-oil soaps.

Tallow's fatty acids:
lauric 2
myristic 6
palmitic 28
stearic 22
ricinoleic 0
oleic 36
linoleic 3
linolenic 1

Lard's fatty acids:
lauric 0
myristic 1
palmitic 28
stearic 13
ricinoleic 0
oleic 46
linoleic 6
linolenic 0

Why, then, can you not get a reasonably decent soap using 100% cocoa butter? Sure, its stearic acid is higher, but that can't be why the single-oil tests that I've read say it barely lathers, can it? So why do pure lard and pure tallow soaps lather, and cocoa butter doesn't?

Cocoa butter:
lauric 0
myristic 0
palmitic 28
stearic 33
ricinoleic 0
oleic 35
linoleic 3
linolenic 0

Avocado butter isn't too wildly different from lard, but I've never heard that it makes a good single-oil soap, either.

Avocado butter:
lauric 0
myristic 0
palmitic 21
stearic 10
ricinoleic 0
oleic 53
linoleic 6
linolenic 2

I've also heard/read that large amounts of butters (cocoa, shea, mango, etc.) will reduce lather. Does anybody know WHY? If it's not their fatty acid composition, then what is it?

I'm sure this is well-traveled territory, and I apologize if my questions are tedious. But nothing I've read here (or anywhere) really explains this, at least not in a way that seems to address it directly. I've looked, and if the threads are out there, my search terms aren't finding them.

I'd appreciate ideas from anybody who wants to share!

 

[cmzaha]

If you check the numbers you will see there is no Myristic or Lauric in avocado butter or coco butter. They are the bubbly fatty acids

 

[JBot]

True, but lard has zero lauric and only one myristic, while tallow has a little bit more than lard (8 combined), but that's not much. Olive oil has none at all, and Castile soap still lathers. This brought me to the conclusion that lauric and myristic are not why 100% lard soaps are fine while 100% cocoa butter soaps are lame.

 

[The Efficacious Gentleman]

If you look at shea butter verses lard in the calc, the numbers are also very similar - and yet they are actually very different things. I'm not sure if the answers lie in soapcalc itself for this one, or if we need to look elsewhere.

 

[JBot]

Exactly. I'd be very interested in any resources that might help me understand how and why.

"Unsaponifiables" come to mind. But what are unsaponifiables? Other than being the parts of a fat that don't saponify, I mean. What exactly are they/what are they made of? Are they a large enough proportion of a fat to be responsible for this sort of thing?

 

[The Efficacious Gentleman]

You can also look at the chemical structure, which is different between to two. As to whether or not that is the "why" is another matter.......................

 

[galaxyMLP]

You also have to realize that there are other longer chain (and shorter) fatty acids that are not being included. I remember that some fats we tested at the food testing lab had pretty high levels of the long chain fatty acids. Maybe they create some of the undesirable characteristics?

 

[topofmurrayhill]

Good thoughts on other fatty acids or unsaponifiables, but I don't think we have to resort to that. You can sometimes find more detailed analyses, and it seems that the effect of mystery components in the oils we typically use is usually likely to be drowned out by the numbers you're seeing in these fatty acid breakdowns.

There are a lot of similarities, but that doesn't mean the differences between these oils don't answer the question. First you see that the ratio of oleic (and linoleic) to stearic is the big variable accounting for the different iodine values (saturation or hardness) of these oils. Despite their similarities, cocoa butter, tallow and lard are very different in this regard.

All things being equal, the softer soaps will have an easier time expressing their lathering qualities. Tallow can get a little boost from its shorter-chain fatty acids. Lard is the softest and has some fatty acids that can make creamy lather when dispersed, and a little extra linoleic that has been shown to bubble.

To my eye, the numbers in question don't suggest that all these oils should make similar soap or be good for single-oil soaping.

 

[dixiedragon]

In my very-non-technical understanding, oils like shea, avocado and cocoa butter are high in unsaponifiables - which are great to nourish skin but are not great for lather. Tallow, lard and palm are not high in unsaponifiables.

 

[JBot]

You can also look at the chemical structure, which is different between to two. As to whether or not that is the "why" is another matter.......................

I would love to look at that, I will see what I can turn up with an online search!

You also have to realize that there are other longer chain (and shorter) fatty acids that are not being included. I remember that some fats we tested at the food testing lab had pretty high levels of the long chain fatty acids. Maybe they create some of the undesirable characteristics?

Good point; hopefully when I'm searching for chemical structure information I can find some of this, too.

Good thoughts on other fatty acids or unsaponifiables, but I don't think we have to resort to that. You can sometimes find more detailed analyses, and it seems that the effect of mystery components in the oils we typically use is usually likely to be drowned out by the numbers you're seeing in these fatty acid breakdowns.

There are a lot of similarities, but that doesn't mean the differences between these oils don't answer the question. First you see that the ratio of oleic (and linoleic) to stearic is the big variable accounting for the different iodine values (saturation or hardness) of these oils. Despite their similarities, cocoa butter, tallow and lard are very different in this regard.

All things being equal, the softer soaps will have an easier time expressing their lathering qualities. Tallow can get a little boost from its shorter-chain fatty acids. Lard is the softest and has some fatty acids that can make creamy lather when dispersed, and a little extra linoleic that has been shown to bubble.

To my eye, the numbers in question don't suggest that all these oils should make similar soap or be good for single-oil soaping.

This is terrific. Thank you.

In my very-non-technical understanding, oils like shea, avocado and cocoa butter are high in unsaponifiables - which are great to nourish skin but are not great for lather. Tallow, lard and palm are not high in unsaponifiables.

Anybody know what unsaponifiables are made of? I'd imagine it varies from one fat to another, but presumably it varies within a certain set of "stuff," right?

 

[dixiedragon]

Here's a very technical article about cocoa butter:
http://nfscfaculty.tamu.edu/talcott/courses/FSTC605/Class%20Presentation%20Papers-2015/Review-Cocoa%20Butter.pdf

Pretty interesting! It's mostly about using substitutes for cocoa butter in chocolate, less so about soaping.

 

[topofmurrayhill]

Anybody know what unsaponifiables are made of? I'd imagine it varies from one fat to another, but presumably it varies within a certain set of "stuff," right?

You're right. This isn't particularly my expertise, but there are such categories.

There are wax esters, which in some cases are essentially a major characteristic of the oil (jojoba) and in other cases extracted as a minor by-product that you can buy separately (RBO and rice bran wax).

There are tocopherols, forms of vitamin E and such.

There are sterols, which are complicated and I don't know much about, but you can buy something called "super sterol liquid" from B&B suppliers if you want to find out whether they contribute anything to your soap.

Maybe more, but I think those cover a lot of it.

Here's a very technical article about cocoa butter:
http://nfscfaculty.tamu.edu/talcott/courses/FSTC605/Class%20Presentation%20Papers-2015/Review-Cocoa%20Butter.pdf

Pretty interesting! It's mostly about using substitutes for cocoa butter in chocolate, less so about soaping.

Thanks! I love articles like that. It's been filed away. I added up the sterols and if I got it right (there are a lot) they amount to 0.28%. Maybe someone can double check that. There are also longer-chain saturated fatty acids (C20 and C22) amounting to 1.2%.

 

[engblom]

I have noticed that the longer a chain becomes, the less it gives lather unless there is a double binding somewhere in the chain.

Lauric, myristic, palmitic and stearic all lack double bindings. If something contains a lot of stearic, it will not lather well as it is a long chain. However, if you mix it with something short as Lauric, it will produce creamier lather because it seem to inhibit big bubbles.

Stearic, oleic, linoleic and linolenic all have the same length but differs in double bindings. As I said before, stearic has no double bindings and will not lather almost at all, but as soon as you add even one double binding as in oleic, you begin to get lather. When you get to linolenic, with 3 double bindings you get very much lather.

When I made liquid flax-seed oil soap (rich in linolenic and linoleic), it was one of the best lathering liquid soaps I have ever seen. Still soapcalc lies telling it does not lather at all.

The values coming from soapcalc is simply worthless. It does not take into account superfatting, making a milder soap. Also some fatty acids as caprylic and decanoic, both creating more lather than lauric and myristic, are completely left out from the calculated value. For coconut oil these two fatty acids are 19% of total amount and definitely contributes a lot to the lather and the harshness of the soap. Those two fatty acids are also the reason palm kernel oil makes a milder soap than coconut oil.