Is There a Law That Says You Must Mix Hard Fats & Soft Oils

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DeeAnna

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I'm sure a tallow and cocoa butter soap would be firm, possibly even brittle, but does that qualify as "too hard"? I have no idea. What criteria would you use to determine whether a soap is hard enough or too hard or too soft?
 

DianaMoon

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I'm sure a tallow and cocoa butter soap would be firm, possibly even brittle, but does that qualify as "too hard"? I have no idea. What criteria would you use to determine whether a soap is hard enough or too hard or too soft?

Too hard - cracks, is brittle. Doesn't hold together.

Anyway, my question is really, is there a problem mixing one hard fat with another?
 

IrishLass

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Although I've never made such a recipe, I'd be concerned that the resulting soap would be too brittle and prone to breakage once whittled down to a smaller size through normal usage. And being the bubble fanatic that I am, I would also be concerned with the lack of bubbly lather with such a recipe.


IrishLass :)
 

Zany_in_CO

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I don't know if this helps or not, but Dr. Bob McDaniels wrote about the "INS" (Iodine-to-Sap) value in a soap formula. An INS value of 160 is (so-called) "perfect" which we all know ain't necessarily so... other factors come in to play, like which fatty acids play nice together. But it can function as a predictor of likely results. I've seen soaps with INS values as high as 185 -- great for making transparents.

ETA: Whatcha think?
Tallow & CB.png

I guess the best answer to your question is that there are no rules as such, but there are guidelines to help you get to where you want to go.
 
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DianaMoon

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Although I've never made such a recipe, I'd be concerned that the resulting soap would be too brittle and prone to breakage once whittled down to a smaller size through normal usage. And being the bubble fanatic that I am, I would also be concerned with the lack of bubbly lather with such a recipe.


IrishLass :)

Yet I've heard of pure beef tallow soap that lathers up a storm.

My concern was after complete curing that it would be too brittle.

I guess there's only one way to find out.

A Swiss soaper named Evik did a neat experiment of one oil soaps in which she experimented with a variety of one oils and tested them at intervals up to 15 months. But not beef tallow. I think she is vegan.
 

dixiedragon

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There's no "law" against it - meaning a 100% hard oil soap will still be soap. It just won't be very good soap. But if you are curious, then try it! I'd recommend a small batch.

A tallow/cocoa butter soap will have several problems - I don't think it will lather well, because the unsaponifiables in cocoa butter can kill lather and there's no coconut to boost it back up. Also, it thicken VERY quickly.
 

DeeAnna

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A brittle soap won't crack if you cut it at the right time with the right cutting tool. It certainly won't fall apart if you are sensitive about when to do things. Just the same as working with a soap that's softer than usual. It's all about the timing.

I'm with the others -- make this soap if you want to and see what you think. There's no harm in that, and you might learn something about what you like and don't like in a soap.
 

DianaMoon

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There's no "law" against it - meaning a 100% hard oil soap will still be soap. It just won't be very good soap. But if you are curious, then try it! I'd recommend a small batch.

A tallow/cocoa butter soap will have several problems - I don't think it will lather well, because the unsaponifiables in cocoa butter can kill lather and there's no coconut to boost it back up. Also, it thicken VERY quickly.

Wow, I wasn't all that aware of the unsaponifiables aspect...I just looked up a table and the one with the highest amount is fractionated coconut oil, which I always thought wasn't used in soapmaking!

http://www.certified-lye.com/lye-soap.html
 

dixiedragon

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IMO, fractionated coconut oil general isn't used in soap making because there isn't a point in spending the extra $ to use fractionated rather than regular. Although it would be interesting to do some kind of comparison! I would not haves guessed fractioned had a higher SAP value than regular!
 

dixiedragon

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re: unsaponifiables - I've made a soap that is 50% shea butter. I got the recipe on here, don't remember which poster.
Castor 5
Coconut 20
Shea butter 50
Sunflower 25
2% superfat.

The 2% superfat helps to boost lather, since the high level of unsaponifiables in shea butter kills lather. I like this bar a lot. It seems to need a longer cure than a lard soap, though.
 

DianaMoon

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Although it would be interesting to do some kind of comparison! I would not haves guessed fractioned had a higher SAP value than regular!

But maybe there is. It has a higher value than stearic acid, which is not terribly high, according to this list.

I say maybe becausee now I'm talking about things I have zero clue about -- having just learned about the drag effect of unsaponifiables, from you! I'm certain that "it's complicated".
 

DeeAnna

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Yes, FCO has a higher sap value. Saponification value is basically a measure of how many molecules of NaOH are needed to saponify a given weight of a particular fat. If the fat molecules are small, more of these fat molecules can fit into 1 gram. Fewer molecules fit into 1 gram if the fat molecules are large.

Fat high in lauric and myristic acid and even shorter fatty acids have higher sap values for this reason. That's why coconut oil has a higher sap value than fats such as lard, tallow, and olive which are high in palmitic, stearic, oleic, and longer fatty acids. Compared to regular coconut oil, FCO contains even more of the shorter fatty acids, so its sap value is higher than coconut.

Fats with a higher unsaponifiable content will also have a lower sap value. Unsaponifiable content is not usually a big issue, however, except for fats like shea or avocado. Some people insist olive oil or pomace olive has a high unsaponifiable content, but the commercial standards for olive oils do not permit excessive unsaponifiable content. There are also some ingredients we use in soap making that aren't really fats such as jojoba, beeswax, pine tar, rosin, etc. They don't saponify per the strict definition of saponification, yet still consume NaOH. These not-fat ingredients have "sap values" that are not necessarily related to their molecular size.

The big reason why I don't recommend using FCO for making soap is because FCO soap has a high % of lauric and shorter fatty acids. Soap made with FCO is even more drying and irritating to the skin than soap made from regular coconut oil. Even normal not-terribly-sensitive skin will react to this type of soap by becoming taut, dry, and eventually irritated.
 

earlene

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How did it lather?
I don't have my notes handy, as I am not currently at home, but as I recall, I was not overly impressed with it as a single oil soap, other than I liked it's cocoa fragrance, which did carry through to the unscented soap. Some people don't like the natural scent of cocoa butter, but I really like it myself.
 
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