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Hot Process and Superfatting

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DianaMoon

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I thought I understood the concept of superfatting soap with respect to cold process soap.

Here is my understanding and if I’m wrong, please correct me. You plug your values into a reliable calculator and the lye will saponify everything but the percentage you’ve chosen. You don’t add 5% after trace. It's not extra - the superfat is baked into the formula.

I realize that I’m leaving out a lot of details, such differing rates of saponification, etc. but I’m just getting after the big picture.

BUT --

With hot process, it seems that you do add extra oil to superfat after cooking/saponification. Am I right? Wrong? If so, how do you calculate how much to add? (Do you take 5% of the total oil and add that?)
 

Zany_in_CO

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Yes, Diana, you got it!

FYI: These are the default settings for lye, SF and fragrance on SoapCalc:
LYE & SF.png
#3 Water: I advise Newbies to use the default settings at first. Later, you can experiment with the next button down, Lye Concentration, and type in 33% for your water amount -- this is the setting favored by many soapers. Later you can try the Water:Lye Ratio button and type in 3:1 for liquid soap if using KOH.

#4 Super Fat: 5-6% works well for most soaps. I choose whichever one is closest to a whole number rather than a decimal. LOL But that's just me. If making Olive Oil Castille, I use 0% SF. If making salt bars, I believe that calls for 20% SF. Point being, you can change the % depending on the soap you're making.
#4 Fragrance: I like 0.85 for most FOs; for EOs, it varies; and 1 oz/lb for a stronger scent.

So, whether making CP or HP, it's up to you whether you just soap away, or take out 5% of the oil(s) to add later -- after trace for CP; after the cook for HP. It's just a personal preference. Some say it makes no difference; some say it's better to add the SF oil(s) at the end to avoid the heat of saponification, esp. in HP.

For me, I don't add SF at the end because I'm likely to forget to do that! :oops:
 

DianaMoon

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I'll give an easy example. My recipe is 5% superfat, I'm hot processing, 1000 grams of oil altogether, I would keep out 50 grams and add that after the cooking?
 

The Efficacious Gentleman

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Yes. And no.

If you just plug it all in to a soap calc and keep that 5% oil till the end, it might not be 100% right.

The calcs work out how much lye would be needed to saponify all oils apart from x% of each oil, X being the lye discount. You're not giving it what it's expecting. You're giving it less of one oil and more of the others. It's at a small amount, of course, but the calculation would be wrong.

I usually plug the recipe in without my 5% oil and set the lye discount to 1%. So in your case I would make a 950g calculation at 1% lye discount, then add my 50g of oil after the cook
 

earlene

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I thought I understood the concept of superfatting soap with respect to cold process soap.

Here is my understanding and if I’m wrong, please correct me. You plug your values into a reliable calculator and the lye will saponify everything but the percentage you’ve chosen. You don’t add 5% after trace. It's not extra - the superfat is baked into the formula.

I realize that I’m leaving out a lot of details, such differing rates of saponification, etc. but I’m just getting after the big picture.

BUT --

With hot process, it seems that you do add extra oil to superfat after cooking/saponification. Am I right? Wrong? If so, how do you calculate how much to add? (Do you take 5% of the total oil and add that?)
Diana, your first explanation is correct and has been tested scientifically by Dr. Kevin Dunn. In this article, where he reports on the experimental process and findings.

The same will happen with HP if you add all the oils at the start, rather than holding out your specific oil you hope will become the SF. It is entirely up to the individual soapmaker to choose which method to use for Superfatting in HP. Some are adamant that adding a specific oil after the cook guarantees that particular oil will be the SF rather than not knowing which oils or combinations thereof end being the SF and theoretically, it does make sense. But how much does it really matter? For me, I don't really care enough to add that extra step. Since I prefer a lower SF to begin with, it really just is not worth it to me to hold out 2 or 3% of oils to add at the end.
 

Saffron

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For HP I use the superfat (usually shea butter) as a carrier for the EO and add it after the cook. It makes the cooked soap batter a bit more fluid and easier to stir and incorporate the EO evenly into the soap. Also helps with spooning the batter into the moulds. I then let it cure for at least 4 weeks before use.
 

dixiedragon

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I'll give an easy example. My recipe is 5% superfat, I'm hot processing, 1000 grams of oil altogether, I would keep out 50 grams and add that after the cooking?
That's what I do. Of course, I typically over-pour by a bit - 132 grams instead of 130, here and there. So my 1000 gram batch is probably about 1020. It would probably be safest to set your superfat as 6% in the lye calculator and then hold back 5% of oils.
 

DianaMoon

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Diana, your first explanation is correct and has been tested scientifically by Dr. Kevin Dunn. In this article, where he reports on the experimental process and findings.

The same will happen with HP if you add all the oils at the start, rather than holding out your specific oil you hope will become the SF. It is entirely up to the individual soapmaker to choose which method to use for Superfatting in HP. Some are adamant that adding a specific oil after the cook guarantees that particular oil will be the SF rather than not knowing which oils or combinations thereof end being the SF and theoretically, it does make sense. But how much does it really matter? For me, I don't really care enough to add that extra step. Since I prefer a lower SF to begin with, it really just is not worth it to me to hold out 2 or 3% of oils to add at the end.
You've caught my confusion here. But you cleared it up - thanks. I'll probably just have to do two batches and see what the difference is - adding the superfat after cook, and adding it at the outset. If there isn't enough lye to saponify everything, then that should be that.
 

DianaMoon

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For HP I use the superfat (usually shea butter) as a carrier for the EO and add it after the cook. It makes the cooked soap batter a bit more fluid and easier to stir and incorporate the EO evenly into the soap. Also helps with spooning the batter into the moulds. I then let it cure for at least 4 weeks before use.
I was wondering about that factor.
 

DianaMoon

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Yes. And no.

If you just plug it all in to a soap calc and keep that 5% oil till the end, it might not be 100% right.

The calcs work out how much lye would be needed to saponify all oils apart from x% of each oil, X being the lye discount. You're not giving it what it's expecting. You're giving it less of one oil and more of the others. It's at a small amount, of course, but the calculation would be wrong.

I usually plug the recipe in without my 5% oil and set the lye discount to 1%. So in your case I would make a 950g calculation at 1% lye discount, then add my 50g of oil after the cook
I'm afraid I don't understand this at all.
 

dixiedragon

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I'm afraid I don't understand this at all.
I think what EG is saying is that not all oils use the same amount of lye. Check out this chart:
http://www.certified-lye.com/lye-soap.html

For example, PKO has a sap value of .1777 which is relatively high. So if you hold back 5% of that, there might be a tiny bit of free lye left in the soap, because the average of most oils is around .13-.14. But, again, it would be miniscule amounts. And this is why you round oil and water up and lye down!

So while I think that EG is technically correct (the best kind of correct), for our intents and purposes you are correct. If you have calculated 5% superfat and you hold back 5% of your oil until after the cook, that oil will be (mostly) unsaponified in the final product.
 

DianaMoon

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I think what EG is saying is that not all oils use the same amount of lye. Check out this chart:
http://www.certified-lye.com/lye-soap.html

For example, PKO has a sap value of .1777 which is relatively high. So if you hold back 5% of that, there might be a tiny bit of free lye left in the soap, because the average of most oils is around .13-.14. But, again, it would be miniscule amounts. And this is why you round oil and water up and lye down!

So while I think that EG is technically correct (the best kind of correct), for our intents and purposes you are correct. If you have calculated 5% superfat and you hold back 5% of your oil until after the cook, that oil will be (mostly) unsaponified in the final product.
I totally understand that and I confined my example to one oil so as not to confuse the issue.

"I realize that I’m leaving out a lot of details, such differing rates of saponification, etc. but I’m just getting after the big picture."

There seem to be two factions. One faction says that in hot process soap making, the superfatting is added after cook. The other factions says no, it's the same as in cold process, the amount of lye will saponify the oils regardless, depending on how much lye you put in.

That's all. But since I didn't make myself clear in the first place, let me rephrase it.

Superfat is the fat in the soap recipe that does not become soap. In cold process, this takes a while. How long, doesn't matter, the point is, when you pour into the molds the mix has not completely saponified. It will, and there will be some superfat if that has been calculated.

In hot process, the saponification occurs completely during the cook. If I superfat at the beginning, how is this different from cold process? Is this just personal preference?
 
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DeeAnna

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What Dixie said is good enough. Set up your recipe per normal and just hold back some of the fat for the superfat as y'all have been saying. It will be fine. I understand what The Gent is saying and I appreciate where he's coming from, but after long, long discussions on this matter in the prehistoric past, I've decided a close approximation is plenty good enough for most people most of the time.

"...In hot process, the saponification occurs completely during the cook. If I superfat at the beginning, how is this different from cold process? Is this just personal preference?.."

Hot process with all the fat added up front isn't greatly different than cold process.

Yes, it's all about personal preference. And it's often about soapers believing the myth of HP soap being fully cured in a few days after it's made.

Hot process with some superfat held back and added after saponification is somewhat different than cold process or "all in the pot HP". To some extent the superfat will remain intact for awhile after the soap is made, but there is no guarantee that this superfat will remain intact forever 'n ever. Or even for some months.

Since soap is a salt in the sense that chemists talk about salts, soap molecules don't mind trading bits and pieces of themselves with their neighbors, and it's likely the superfat, especially if it's a polyunsaturated fat, is broken down into simpler chemicals -- diglycerides, monoglycerides, and fatty acids -- as time passes. So that exotic miracle superfat very likely won't stay intact for long.
 

dixiedragon

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I think the confusion may be that (generally speaking), we recommend that you include your 5% superfat in with your recipe, but hold that 5% special superfatting oil until the end. Some people get confused and think that they don't include that 5% special oil in the recipe itself.

But if you add it all at once, or at the end, your results won't be disastrous. When I first started soaping, the "rule" was that you added that 5% at the end at trace for CP.
 

DianaMoon

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I think I'm getting it now.

Saponification is saponification, whether it is cold process or hot. In this one sense soapmaking is like driving to a certain destination. You get there whether you go 80MPH or 30MPH.

Superfatting will happen (or not, as DeeAnna seems to imply) regardless of when the excess fats are added.

Perhaps adding after saponification adds a bit of extra control over the process, but in the long run it doesn't make that much of a difference.

Thanks, this demystifies things considerably. I was very confused & daunted by hot process. But now not so much.
 

dixiedragon

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Pretty much! There are some rules that are more "rulier" than others - for example, don't add castor as your superfatting oil - saponified castor boosts the bubbles, but free castor does not.

There is some hard science here (like from Kevin Dunn's research and our own Deanna), but a lot of it is based on preference, what people have found that works for them, and flat-out superstition - or would that be soaperstition?
 

DianaMoon

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Pretty much! There are some rules that are more "rulier" than others - for example, don't add castor as your superfatting oil - saponified castor boosts the bubbles, but free castor does not.

There is some hard science here (like from Kevin Dunn's research and our own Deanna), but a lot of it is based on preference, what people have found that works for them, and flat-out superstition - or would that be soaperstition?
LOL. Today seems to be the day for sudsy humor. (I posted something about my Peru Balsam & Jojoba concoction, which I call, PB&J.)

And thanks for the tip about castor oil.
 

DianaMoon

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Yes, it's all about personal preference. And it's often about soapers believing the myth of HP soap being fully cured in a few days after it's made.
Then why hot process at all? Does it at least cut down on cure time?
 

dixiedragon

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IMO, week-old hot process is milder than week-old CP. HP cure time equals (or exceeds) CP cure time because people often use more water in it (to get a smoother pour) and so it needs more time for the water to evaporate.

to me, the benefit of HP is in what ingredients and FOs you can use. I have an apple cider that is delicious...but it causes the soap to seize HARD. Like, 30 seconds from emulsion to cold mashed potatoes.

I also really like to HP honey beeswax soap.
 

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You can use less FO in HP soap, since the scent can be added after saponification is over and there is little or no active lye to mess with the fragrance.

Some types of soap are better made with HP, such as soap with beeswax or other waxes, or shave soap with stearic acid, or soap with fragrances that are difficult to use with a cold process method (FOs that rice or seize, for example). Pine tar soap can be really tricky to make with cold process, so some people make it with a hot process method instead. Rosin soaps are another example of a soap tricky to make CP.
 
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