Lye & Oil

[Teri Collins]

I've been wondering...go figure... if the oil is eat'n up by the lye when mixed...does the oil used as your base oil become, how do I put it...a non issue...If I use a cheap oil as my base & save my High grade Olive oil as part of my superfat oils...do I have to include that base oil in my list of ingredients.?..

 

[Nate5700]

Well, I'm not speaking as an expert or anything, but I don't think that's how it works. Different oils will produce different types of soap dependent on the fatty acids that compose the oil. It's the mixture of your base oils to get a certain fatty acid "profile" that determines the characteristics of the soap.

In cold process any superfat that you add separately will just mix in with everything else and get saponified all together. I suppose you could hot process and add the superfat oils after the cook if you wanted to keep them separate, but I don't know if that's something people typically do.

Any oil that mixes with the lye will have to be on your list if you're using a calculator.

Depending on what you mean by "cheap oil" it doesn't sound like something I would try. That said, from what I understand you don't need to use your high grade olive oil in soap either since whether you're using extra virgin (high grade) or pomace (low grade) the fatty acids are pretty much the same, so I wouldn't waste money buying high grade oil to make soap. But I wouldn't just throw in cheap vegetable oil and call it good either.

 

[earlene]

Yes, you do have t list it in your ingredients. It's either the 'what goes into the pot' format, or 'what comes out of the pot' format. You have to list them all.

For example, if what goes into the pot is cheap coconut oil, you list either coconut oil or Sodium Cocoate.

 

[shunt2011]

If you are doing CP there is no guarantee what you add as a superfat is what is actually going to be the superfat. The lye will take what it wants. The only way to somewhat pick your SF of choice is doing HP. Therefore, if CP you just add all your oils/butters in the pot at one time. I don't use cheap oils.

Also, what is your description of cheap oils. I use lard which is fairly inexpensive but makes the best soap.

 

[atiz]

What @Nate5700 said. If the base oils were not "an issue," then all soap would be the same -- but they aren't. It does matter what oils you use. And you do need to list them on the ingredients list, whether for calculations or for labels. It's like.... the flour you put in your cake batter is not technically flour after the bake but you would still list it as an ingredient.

 

[steffamarie]

The oil isn’t eaten up by the lye exactly. One molecule of, say, olive oil, is a triglyceride. It’s three fatty acid chains and a glycerol backbone linking them together. The sodium hydroxide breaks the bonds and the sodium binds with the fatty acid to make the sodium salt of that fatty acid. In the case of olive oil, most of those fatty acids are oleic acid. The glycerol backbone combined with the hydroxyl group becomes glycerin. So depending on the oil and how much of each fatty acid it contains, you’ll have different fatty acid salts at the end - different salts give different results when lathered.

Edit: here is a good video to watch to understand the chemical reaction. This is, however, NOT a great soapmaking tutorial and I wouldn’t recommend you follow his process or safety precautions. He is a chemist, not a soap maker. Some of the things he does and uses could be dangerous.

 

[IrishLass]

Hi Teri- in the USA, if the soap you are making is what is termed by the FDA as being 'true soap' aka soap made by mixing oils, water and lye..... and you are not making any claims such as that it moisturizes or heals or eliminates acne or whatever else.....i.e., it is just labeled as being 'soap'.... then according to the US FDA regulations, you are not required to list your ingredients. But it's smart to list your ingredients because of folks that buy or use your soap might have allergies, etc... If you list your ingredients, Marie Gale is considered to be the source on how to do so correctly: https://www.mariegale.com/ingredient-labels-soap/

For what it's worth, even if you do an 'after-the-fact' superfat, i.e., adding any oil or fat after the main batter is saponified/tongue-neutral, it's not a sure thing that the superfat will always remain uniquely untouched or 'as is', because soap is not a static entity. There's something called 'dynamic equilibrium', whereby the chemistry going on inside the soap (even after saponification is complete) is constantly changing in order for the soap to maintain equilibrium. DeeAnna explains it best here: https://www.soapmakingforum.com/threads/why-is-soap-alkaline.42021/#post-394531.


IrishLass