Teach Soap

I am a new soaper and use Soapmaker software. When creating recipes I use 6% lye discount. Is this another way of saying superfat? I have resently been thinking about using a 7% lye discount for my customers with expecially sensitive skin, will this help? Will my soap last as long on the shelf? What do most of you use for lye discount?
Thanks much.
Helene

My standard is about 5%. Anything more than that and I sacrifice the bubbles that I've come to grow and love as superfat will weigh down the lather.

Ok everyone. I'm in one of my writing moods so lookout:

Imagine going to a dance where the participants are molecules. There are 100 black tuxedos and 100 evening gowns of different colors. The tuxedos are lye molecules and the evening gowns are the oils, butters, fats, etc. All the molecules have to find a dance partner. When making soap, a 1 to 1 ratio (1:1) means that every oil molecule will reacts with a lye molecule to make soap and all of the evening gowns have a corresponding tuxedo partner for dancing. The coupling of a single tuxedo to a single evening gown is saponification.
When you have more evening gowns (oil molecules) than tuxedos (lye molecules), you have" superfat." Let's say you want a 5% superfat. So, at the beginning of your dance, you cut loose 105 evening gowns to find 100 tuxedos partners. 5% of the evening gowns (superfat) will not have a dance partner. So you have to take them back home. These are the ones that are going to be left on your skin after you use the soap. This is your superfat....and the oils that remain on your skin. So a long way to answer your question: yes, I think they're the same thing.

I add my superfat oils at trace but some here believe you can add them all at the beginning because the lye will take what it wants. I disagree but my opine is different....not necessarily wrong as I don't believe you can prove what is better. You should probably duck about now because some flames are sure to follow.

Thanks justkate. I have a way of complicating an explanation.

But you're so entertaining.

I'm blushing.

Ok... I love this debate...superfat up front or at trace? I think if we could find someone going for their doctorate this would make a great study. There would have to be some way to prove that the lye took what comes first or by a priority system of its own choosing. Like wanting all the yellow gowns over the blue gowns unless a red one comes along
Thanks for stimulating my mind today!

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Susie
Sometimes A Mistake is so much fun, You just have to do it again!

Ok Bubbles 2.....you asked for it. Assuming you read what I already wrote about the dance then finish reading...

Let's complicate things a little more about the dance. Let's pretend that each evening gown is a different color. Coconut Oil is wearing a red dress, Olive Oil is wearing a white dress, and Palm Oil is wearing a blue dress. If you turn loose all the evening gowns at the beginning of the dance (add all of your oils including 5% superfat at the beginning). You know there will be 5 dresses without partners, but you cannot know which colored evening gowns are going to be left over -- or which oils you're going to leave behind on your skin. You could have 2 coconut oil, 2 olive oil and 1 palm oil OR 3 olive oil and 2 palm oil. There are dozens of combination of colored dresses that are left over after the rest find partners. The more oils you use in your soap, the higher the number of variables, and it's unlikely that any two batches of soap with the exact same recipe will have the same colored dress combination. This is if you add all of your oils including your superfat oils at the beginning. With me so far? Good.

Now let's say that the dance begins with exactly 100 tuxedos and 100 evening gowns of different colors. After they are all matched and all the dancing partners are assigned (saponification has begun), then an extra 5 pink evening gowns arrive (Shea butter)—these are your superfats added at trace. Because the Shea butter is added only at trace – after saponification has already begun – the Shea butter remains on your skin after you use the soap.

I believe this is the difference between adding your superfat oils at the beginning or adding them at trace and after saponification has begun. Granted, saponification takes place over weeks but the corresponding molecules have already been assigned.

Yes, I read the nice story about the wolves, sheep and puppy dogs. I believe my logic is correct.

The way I understand it, some of those tuxedos could still change their mind after they have a partner and go to dance with a pink instead of a blue or a red.

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Irena
Closed minds are like faulty parachutes; they refuse to open.

Thats what I was worried about Those partner switchers. Has there ever been a 'scientific' experiment on this?
So SuperSoaper do you notice a difference - like do the same recipe both ways?

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Susie
Sometimes A Mistake is so much fun, You just have to do it again!

Think of it this way. If there was a "partner-switcher", most all soaps would feel the same way on your skin if you used the same combination of oils....but in varying concentrations. I don't think it's possible. Say every batch of soap you made was with coconut, palm and olive. But instead of using 20% coconut oil, you used 80% coconut oil. Applying this logic, the two batches of soap would feel the same. It just doesn't make sense.....to me anyway.

I've tried doing it both way bubbles and it's difficult because I know which is which. My wife has very sensitive skin and 4 out of 5 times she chose the one where I added the superfat at trace. To do a good side-by-side comparison, all things would have to be exactly the same.....or a "control group" if you remember your chemistry classes. The relative humidity would have to be the same at each showering event, the water temperature would have to be the same, the amount of secreted body oil would have to be the same....etc. It's just too many variables to control. Because of this, we may never know. I have a laboratory but it's for agricultural genetic sequencing and not set up for this. If anybody out there works for a laboratory that has a GC-MAS Spec (gas chromatograph mass spectrometer) that would narrow it down a little. I don't have access to a GCMS or I would have tried it a long time ago.

The truth is that I'm a novice soapmaker and have only been making soap for 6 years. I've made soap about 4 times a week over those 6 years but I still have a lot to learn about the art and the science. There are many here who have a lot more soapmaking experience that me. This is just one of those things that I don't think can be proven without extensive study. I do have a strong background in science and this is what makes sense to me. But that doesn't mean it's right.....or wrong.

From a newbie aspect, this is a wonderful conversation

I love that people here are so informed. It's helping me to understand this new world I've stumbled into

Great explanations of the two theories. I would be interested in the studies if they were ever conducted.

Here's an interesting article about superfatting vs. effective lye discounting.

http://www.bloomworksoap.com/ARTICLES/s ... scount.htm

Lye doesn't see oils, only fatty acids. The ones that saponify slowest, like linoleic acid for example, are the ones that remain in the soap. That's my theory. Most of the saponification hasn't happened by the time you reach trace. Let's hypothetically say that 5-10% of your saponification is complete by trace. That means that 90-95% of your lye has yet to become friendly with the fats, and your lye doesn't care which fats it eats up, whether base oils or those added at trace. Those fats added at trace might exist in the final product by an infintesimally (sp?) increased percentage.

Now this is not true if you add your superfat oil after the soap is cooked.

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Irena
Closed minds are like faulty parachutes; they refuse to open.

I don't know of any studies that have been done, but there was someone on another forum who had her superfatted-at-trace soap analyzed by a lab and was surprised to find that her superfatting oil didn't end up as a superfatting oil. The lye chose a different dance partner.

I don't really care how other people do it, but I'm on board with Soapbuddy's theory.