Mild soap, what does it mean?

[Alfa_Lazcares]

Okay so since I’m very new to this I am still trying to get a grasp on the basic concepts of soaps and soap making in general. And this is something i still dont quite get.

I get that a lot of people think of a mild soap as a soap that has a low or neutral ph. But i also get that a soap can not be a soap if its got a neutral ph cause chemistry. So i understand that lowering the lye wont make a mild soap. I also get that adding well, additives wont make a soap mild by lowering the ph because again, chemistry. In so many words thats the right concept, right? A soap can not have a neutral ph because that is not soap.

So for making a mild soap we have to think of other things instead of the ph. And here i am talking about soap and not detergents.

So what or how can i formulate a mild soap and what exactly are we refering to when we say, for example that castille soap is mild?

Is it the clensing? I know coconut is quite cleansing and so making a soap with a high % of coconut will not be mild. Is that right?

I have this idea, by reading recipes and coments that oils like olive or avocado make a mild soap, but why is that?

In other words what exactly is what i should be looking for (or at) to determine if a soap will be mild?

Does it also has to do with its conditioning properties? For example on the original shampoo bar recipe up there, people were calling it a very mild soap, and it is full of oils that are not hard, so is that it? Soft oils make a mild soap?

Just to be clear. i am not trying to look in to how to lower the ph of the soap to make it mild because i understand that is not possible. But i dont get what makes a soap mild or what are people talking about when they call a soap recipe mild.

Please enlighten me! Haha. Maybe obvious but i dont get it yet. If it makes it easier, i made a chart of the properties of some oils which point to the amount of acids they have (using the soapcalc charts when you select the oils) so pointing me to that numbers are easy to reference for me. I have an idea that that has to do with it?

Hope i didnt confuse you cause i might be begining to confuse myself and thanks in advance!

 

[The Efficacious Gentleman]

You're right in that it's not about the pH at all, not the amount of lye. You're also right that it is to do with the coconut (or other cleansing or 'stripping' oils) and also the oil make up.

All soap cleans, so the cleansing number is somewhat badly named. The oils high in cleansing mean, in part, that they can strip more natural oils from your skin. This can be offset by using a higher lye discount (or superfat) so that there is more actual oil for the cleansing soap to bind with rather than just your skin oils. A 100% coconut oil soap should be awful, but if you use a 20% superfat then it's okay.

But a high superfat isn't always possible. In a more balanced recipe, that much superfat would make a bar that doesn't lather and might well leave you feeling more greasy than before you washed! So we can use less cleansing oils. This will be a balance more particular to you - some people can't go over 15% coconut, other happily use 30%. You'll have to find what works for you.

As for the other oils, they might well have a similar fatty acid profile to other oils (avocado and olive, for example) but then there are also parts of an oil which don't saponify. These unsaponifiables can have an impact on the soap, for better but also for worse in some cases.

 

[Sandra@SS]

'Mild' is also an individual quality.
An individual may find a classically 'mild' soap formula irritating, so it isnt 'mild' for them specifically, ie olive oil based formulas can be irritating to some people, even though it is meant to be a 'mild' product

 

[shunt2011]

I agree with Sandra. Many consider Castille (100% OO) to be gentle. I personally find it drying and don't like it. I have made a 100% CO soap with a 20% SF and I liked it just fine. I prefer using salt soap instead of just CO. My favorite is a blend of Lard/oils/butters. It will take a lot of trial and testing to see what will work for you. Everyone is different. I can tolerate a higher CO than some. I also keep my SF fairly low and adjust my recipes accordingly.

 

[lsg]

I like to use 30% coconut oil with plam, Castor and rice bran, (or olive oil). My family does not find this soap drying. Others may not be able to tolerate a soap with a high percentage of coconut oil.

 

[Alfa_Lazcares]

You're right in that it's not about the pH at all, not the amount of lye. You're also right that it is to do with the coconut (or other cleansing or 'stripping' oils) and also the oil make up.

All soap cleans, so the cleansing number is somewhat badly named. The oils high in cleansing mean, in part, that they can strip more natural oils from your skin. This can be offset by using a higher lye discount (or superfat) so that there is more actual oil for the cleansing soap to bind with rather than just your skin oils. A 100% coconut oil soap should be awful, but if you use a 20% superfat then it's okay.

But a high superfat isn't always possible. In a more balanced recipe, that much superfat would make a bar that doesn't lather and might well leave you feeling more greasy than before you washed! So we can use less cleansing oils. This will be a balance more particular to you - some people can't go over 15% coconut, other happily use 30%. You'll have to find what works for you.

As for the other oils, they might well have a similar fatty acid profile to other oils (avocado and olive, for example) but then there are also parts of an oil which don't saponify. These unsaponifiables can have an impact on the soap, for better but also for worse in some cases.

Thanks for the long answer! Yes, I get that the "clensing number" is kinda... redundant since a soap is supposed to clean, so it was kinda weird that most of them are at 0 (in soapcalc) and then coconut gets 67, but i kinda figured it was just that coconut is really clensing/stripping.
Is there a chart or something I can look at to know how unsaponifiable an oil isl?


Thank you all for answering. I still don't know what my preference is since I have only been using my first batch I made while still waiting for the rest to cure (a salt bar and a castille soap are in there and we all know those will take a while) and some that I haven't done yet, like a pure coconut and a pure lard, so until I really try those I won't really know my preference so I am kinda going in the dark here, just wanted to get a bit of direction.

Usually a castille soap is mild for a whole bunch of people, though some people dislike it, and the other way around with coconut, is there a reason why the castille is labeled mild? I mean, besides the personal prefence? I'm sorry if that question seems redundan!

 

[psfred]

I think the classic definition of a mild soap is one that doesn't leave your skin feeling dry or "tight" after rinsing it off and drying. I suspect this is in reference to old fashioned "lye heavy" soap made on the farm by "guess & by God" as the Newfie's would say. A fully cured lye heavy soap will have a lot of sodium or potassium carbonate in it, and is very stripping, and it can also have a fairly high pH from residual lye. Will get you clean for sure, but won't feel all that good.

That said, a soap that one person thinks is "mild" won't please another, so experiment and find a recipe or three that suits you!

 

[TFriedman]

You're right in that it's not about the pH at all, not the amount of lye. You're also right that it is to do with the coconut (or other cleansing or 'stripping' oils) and also the oil make up.

All soap cleans, so the cleansing number is somewhat badly named. The oils high in cleansing mean, in part, that they can strip more natural oils from your skin. This can be offset by using a higher lye discount (or superfat) so that there is more actual oil for the cleansing soap to bind with rather than just your skin oils. A 100% coconut oil soap should be awful, but if you use a 20% superfat then it's okay.

But a high superfat isn't always possible. In a more balanced recipe, that much superfat would make a bar that doesn't lather and might well leave you feeling more greasy than before you washed! So we can use less cleansing oils. This will be a balance more particular to you - some people can't go over 15% coconut, other happily use 30%. You'll have to find what works for you.

As for the other oils, they might well have a similar fatty acid profile to other oils (avocado and olive, for example) but then there are also parts of an oil which don't saponify. These unsaponifiables can have an impact on the soap, for better but also for worse in some cases.

Great answer Craig. Are you a chemist?

 

[The Efficacious Gentleman]

No more so than most soapers! I just learnt a lot from here [emoji847]

 

[dixiedragon]

Thanks for the long answer! Yes, I get that the "clensing number" is kinda... redundant since a soap is supposed to clean, so it was kinda weird that most of them are at 0 (in soapcalc) and then coconut gets 67, but i kinda figured it was just that coconut is really clensing/stripping.
Is there a chart or something I can look at to know how unsaponifiable an oil isl?

Usually a castille soap is mild for a whole bunch of people, though some people dislike it, and the other way around with coconut, is there a reason why the castille is labeled mild? I mean, besides the personal prefence? I'm sorry if that question seems redundan!

There are charts that tell you the saponification values of oils - that is, how much lye is needed to saponify a certain quantity of those oils. Skimming the chart, it seems like the more cleansing oils have higher SAP values (coconut is 240, for example, while most are under 200) but I don't know that I'd trust that totally.

I think that castile is thought to be mild because it needs to be aged for a long time, so most folks are going to find a bar of 1 year aged castile to be very mild. But not everybody, obviously!

 

[DeeAnna]

"...the more cleansing oils have higher SAP values (coconut is 240, for example, while most are under 200)..."

I'd change the name from "more cleansing" to "more stripping" if I had my druthers, but you have a point.

Sap values are a rough measure of the size of the fatty acids in the fats, and the "more stripping" fats contain shorter fatty acids (and have higher sap values) than the "less stripping" fats (longer fatty acids, lower sap values).

Think of the 60s "thing" where people tried to find out how many people could stuff themselves into a VW Beetle. More skinny people will be able to fit into the car. Sap value is a measure of how much NaOH or KOH is needed to fully saponify 1 gram of fat. If the fat molecules are made of "skinny" (short) fatty acids, then more molecules of that fat can be packed into every gram, compared to a "not so skinny" fat. That means more NaOH or KOH is needed per gram of fat to convert those skinny molecules into soap.

Soap made with shorter fatty acids has the ability to remove proteins and fats from the skin surface (stratum corneum), thus gradually damaging this layer of skin. Some people's skin is more resistant to this damage than others, but even normal skin will be dried out by repeatedly washing with soap high in these shorter fatty acids.

I do not believe soap made with longer fatty acids is always as mild as the "zero cleansing" value would suggest, although there is a definite trend of longer fatty acids = less drying or irritating to most people's skin most of the time.

A surprising number of people here on SMF, however, say high olive oil soap (high oleic acid) is drying to their skin. Oleic acid soap is made of longer fatty acids, that's true, but the soap happens to also be very soluble in water. More soap on your washcloth = more cleaning = more tendency to irritate.

A soap made with longer fatty acids that is less soluble in water (palmitic and stearic acids) may be less likely to irritate than a soap with longer fatty acids that is more soluble (oleic acid). That might explain why lard and palm soaps are considered mild (these fats are high in palmitic and stearic acids).

 

[Alfa_Lazcares]

Thanks so much for the answers, specially DeeAnna (i was secretly hoping you could give some chemical answer and you did, you don't know me but I have been stalking your aswers to questions posted)

As said I am gonna be making more soaps but it's gonna take a while for them to cure and for me to be able to try them to really know what I like, just wanted some of your opinions, thank you!

 

[The Efficacious Gentleman]

A tip is to make different sorts of soaps, where the recipe is so different. Like a salt bar. That way you get the soap making fix but don't have lots of very similar bars stacking up

 

[Alfa_Lazcares]

A tip is to make different sorts of soaps, where the recipe is so different. Like a salt bar. That way you get the soap making fix but don't have lots of very similar bars stacking up

Haha you read my mind, that’s exactly what I’m doing! I made 3 smallish batches of similarish recipes (not at the same time, mind you) because i liked the first i made and use and i am in the process of tinkering them to see the diferences, and i am working on single oil even smaller batches, one of them is the salt bar (2 weeks old now, still waiting for them to cure more) and next is gonna be the castille. But the waiting, oh, the waiting. I’m still debating on making a pure lard and pure coconut or to add another small % of another oil to them.