Ohhh DeeAnnnnnaaaaa! Come out and play!

[The Efficacious Gentleman]

............ Perhaps it's time to agree to disagree and move on?

Almost! I do feel that for superfatting after the cook in HP there is a much better way than the lye discount method.

It depends on whether you keep the definitions of Superfat and Lye Discount the same all the time -

10% of the of oil mix is not saponfied (option 1)

OR

you used 10% LESS lye than is required to saponify the total weight of oils (option 2)

In CP, these are one and the same thing. But not in HP.

I agree 100% that to do a lye discount (option 2) the whole "Total weight lye minus this and multiplied by the other" is brilliant.

BUT

If you split out the definitions of superfatted and lye discounted in HP, because you have the option of adding in more oil after the cook which you don't have in CP. Adding in more oils after the cook is not lye discounting (option 2), but rather it is superfatting (option 1)

You can have 10% of the oils unsaponified AND the amount of lye used is not the same as 10% less than is required for all of the oils used.

 

[DeeAnna]

"...But does it really matter in large batches versus small..."

Yes, it does matter. While it is indeed true you have to measure out more superfat oil for a large batch vs. small, the PERCENTAGE of superfat in the soap is the same, whether the batch is big or small. If you make 10 oz of soap with 1 oz superfat or 100 oz with 10 oz superfat, the effect is all the same to the soap.

Think about making a cake. If an 8x8 pan of cake calls for 1/2 tsp salt and a double-sized recipe calls for 1 tsp, do you normally just leave out the 1/2 tsp salt if you're only making a small pan of cake? It's just a small amount of salt, so it's surely not important, right?

"... wouldn't a large number of oils versus a small number impact differently..."

No, the number of oils honestly doesn't make a difference. The key issue is the saponification value of the superfat oil vs. the averaged SV of the blended soaping oils however many or few there are. If the superfat SV is about the same as the averaged SV of the mixed soaping oils, just use the simple "% of oils" method. If the superfat SV is quite different than the average SV, use the more complicated "% of lye" method.

 

[FlybyStardancer]

I agree 100% that to do a lye discount (option 2) the whole "Total weight lye minus this and multiplied by the other" is brilliant.

BUT

If you split out the definitions of superfatted and lye discounted in HP, because you have the option of adding in more oil after the cook which you don't have in CP. Adding in more oils after the cook is not lye discounting (option 2), but rather it is superfatting (option 1)

You can have 10% of the oils unsaponified AND the amount of lye used is not the same as 10% less than is required for all of the oils used.

See, I have to disagree. I don't think the method of calculating out lye amounts and SAP values is a lye discount. In fact, it is a true superfat because you're calculating how much oil/butter you'll need based on fat amounts.

Your method works for you, and that's great! However, for those who want to know how much actual fat they're adding, the math version makes more sense.

Your method tells you how much oil you're superfatting with as a percentage of the total oils. However, because different oils/butters have different amounts of fat per unit of oil, it's a less precise way of calculating superFAT. The other method using lye amounts to figure out how much fat you'd need to get a given superfat, and then the SAP value of the oil to tell you how much oil you'd need to get a given superfat.

 

[The Efficacious Gentleman]

Okay - I had always thought that oils/fats were almost 100% fat, and that the SAP values depended more on the type of fat chains rather than particular if, for example, lard has more fat than olive oil.

So my method may not tell you precisely what % of fat inside the fats is saponified or not, but it is much easier for those who don't want to get too involved in the tricky math!

 

[FlybyStardancer]

It seems the confusion is amount of fat by weight, and the amount of fat by number of fatty acid molecules, which will be different based on the type of fatty acid.

Here's my understanding of how SAP values come into play.

1. There are two ends to a fatty acid. The three carbon chain 'fat' end, and the carboxilic acid end.
2. You will always need the same number of lye molecules to convert a give NUMBER of carboxilic acids (as a part of the fatty acid).
3. Different fatty acids will have different molecular weights because of the difference in size of the carbon chain ends (more carbons and hydrogens in the chain equals a heavier molecule). This means if you have n number of oleic acid (C18H34O2), it will weigh more than n number of, say, myristic acid (C14H28O2).
4. Conversely, this means 1g of oleic acid will contain fewer molecules than 1g of myristic acid.
5. This means that you will need less lye to convert 1g of oleic acid than you would 1g of myristic acid, because there are fewer acids for the lye to interact with.

For the purposes of calculating out HP superfat, we are are saying that to be precise, you need to calculate out the superfat percentage based on the number of of fatty acid molecules (so, 8% of all of the fatty acids), which will have different weights depending on which fatty acids are in the oil you're using to superfat.

And yes, your method will give you a superfatted soap.

 

[MzMolly65]

If I add more oil in after the cook, I am adding oils to a 2% SF'd batch of soap, so my extra fat is super fat.

That's what I always thought .. hmm .. I'm not moving camps yet because I just got all this math sorted but that's the mechanics I was struggling with. I understood the math but not the why of it.

 

[ilovesoap2]

I do feel like a child stepping into an adult conversation :shh:

These are my thoughts
Superfat for soap means the amount of oil (regardless of fat content) above and beyond what is needed by the lye in a recipe to make a batch of soap.

So lets say I make a soap with olive and coconut oils at 2% sf, at the end of the cook, I should have that 2% of oils left over correct? Based on Sap values, it may be a little of each oil or it may be only one oil left over, which ever it is, that 2% should be there because it was more than the lye needed. At this point I add my meadowfoam. It should stay in my soap simply because there is no lye in the batch to interfere. My challenge may be how to get it completely incorporated in the soap.

This is assuming I'm using a soap calculator. I am assuming the calc is taking into consideration the sap value of the oils and even though they are using an average, they are still saying if I superfat even 1% all the lye will be used up. This is really clear in my head. The math stuff I've been reading over last hr just has me all sorts of twisted :lolno:

If my thinking is completely wrong though I'll have to keep practicing until I get it.

 

[The Efficacious Gentleman]

That's where I was, and it was the whole idea of SF and lye discount together that had me.

But regardless - my pumpkin seed oil soap is in the moulds! I love you all!

And please don't feel that I was being contrary for the sake of it.

 

[FlybyStardancer]

I do feel like a child stepping into an adult conversation :shh:

Please don't! We're all adults here. Some are just more scientifically- or mathematically-minded than others.

These are my thoughts
Superfat for soap means the amount of oil (regardless of fat content) above and beyond what is needed by the lye in a recipe to make a batch of soap.

So lets say I make a soap with olive and coconut oils at 2% sf, at the end of the cook, I should have that 2% of oils left over correct?

Here's where you're getting confused. Superfat isn't based on the amount of oil-it's based on the number of fatty acids. If you make a soap and run it through the calculator with a 2% lye discount, then you're getting an amount of lye that will react with all but 2% of the fatty acids in the recipe. However, depending on what it's reacting with, you could be left with all of the coconut oil reacted, leaving maybe 3-4% (by weight) of the olive oil unreacted.

Soap calculators are great for cp soap, because you can't choose which oil reacts and which doesn't in a cp, so you only need to know the averages. In that way, the difference between lye discount and superfatting doesn't matter.

Because we're able to pick and chose which oils we want the lye to react with in hp soap, things become a little harder. The amount of lye for a recipe has to be in relation to the NUMBER of fatty acids. Lye, being one molecule, is easy to convert between weight and the number of molecules. Fats aren't so easy to measure the number of, which is why you have to deal with things like SAP values.

 

[FlybyStardancer]

But regardless - my pumpkin seed oil soap is in the moulds! I love you all!

Yay for soap in the molds! <3

And please don't feel that I was being contrary for the sake of it.

Definitely not! I often feel like I'm being perceived that way, when something isn't making sense to me.

 

[ilovesoap2]

Here's where you're getting confused. Superfat isn't based on the amount of oil-it's based on the number of fatty acids. If you make a soap and run it through the calculator with a 2% lye discount, then you're getting an amount of lye that will react with all but 2% of the fatty acids in the recipe. However, depending on what it's reacting with, you could be left with all of the coconut oil reacted, leaving maybe 3-4% (by weight) of the olive oil unreacted.

I was hoping to miss the math class.
I better get on it though..darn!
Thanks for further explaining, it will help whilst I go over this thread again

 

[FlybyStardancer]

Sure, you don't need to know exactly how much in order to superfat your soaps. It just means results will vary depending on what oil you use to superfat.

Sadly, math is everywhere. I hope my explanations helped!

 

[grayceworks]

Ok, I'm going to let you guys try this spreadsheet out, it's nothing fancy right now, because it's a work in progress. Try it, give me feedback, and eventually I'll get it all pretty and stuff. lol

It's very, very, very basic at this point. First figure your base recipe at 0% lye discount (or 1% or 2%) without the superfat oil figured in, in soapcalc. Then in this calculator, you enter the name of the oil, enter the SAP for it from soapcalc, enter what % superfat you want to do, and enter the 0% lye amount from soapcalc. It will tell you how much of your SF oil to add after the cook.

If you've entered a 1% or 2% lye discount instead of 0%, then remember that when you're entering in what SF percent you want to do, because your recipe will already be at 1% or 2% SF from your base recipe oils.

I might get it to figure 0%, 1% and 2% lye discount and oil superfat amounts all as separate options... I started that, but then it was too much for my brain tonight, and it was making too many columns, which means I'll have to do a form with drop-down menus instead, and my brain said NO for tonight. Unless someone good with excel wants to help out. lol

Yes, I know the last column is full of divide by zero errors, because, well, nothing is entered into the SAP or % or Lye column until you enter those in. Then the last column calculates it all for you.

Like I said, it will be prettier later. Just want it functional for now and get feedback on it.


Link to XLS file direct download.

There's also some comments in the boxes that have the little red triangles on the corners.

 

[MzMolly65]

... and let me complicate things a little with a few more questions.

Could you batch the main oils and then separate it into portions, adding a different SF into each portion?
Could you batch the main oils and store it until someone asked for a specific SF and then add it at a later date?
Could this work with Pine Tar as a SF?
Would this same math hold for KOH as well as NaOH?

I look at all my questions and realize, I am a mad scientist at heart.

 

[grayceworks]

... and let me complicate things a little with a few more questions.

Could you batch the main oils and then separate it into portions, adding a different SF into each portion?
Could you batch the main oils and store it until someone asked for a specific SF and then add it at a later date?
Could this work with Pine Tar as a SF?
Would this same math hold for KOH as well as NaOH?

I look at all my questions and realize, I am a mad scientist at heart.

Like calculating two batches separately and then adding the main portions together? Should work, I would think, if you calculated each SF oil properly.

And this would be ideal for master-batching. Have a main oils recipe, and then just separately calculate the SF amount for whichever oil you decide to add to it.

Pine Tar has a SAP value... I think it might work? DeeAnna? lol

The math is the same for KOH and NaOH in this respect, as long as you use the proper SAP value for the type of lye you are using.

Try my spreadsheet thingy! Let me know what would make it easier!

 

[ilovesoap2]

Sure, you don't need to know exactly how much in order to superfat your soaps. It just means results will vary depending on what oil you use to superfat.

Sadly, math is everywhere. I hope my explanations helped!

Actually, still confused ever after going over the thread. Now I just wait for grayceworks spreadsheet

 

[grayceworks]

Link to XLS file direct download.

Actually, still confused ever after going over the thread. Now I just wait for grayceworks spreadsheet

Posted with some basic info up in post #93 above... but here's the link again!

 

[DeeAnna]

--Could you batch the main oils and then separate it into portions, adding a different SF into each portion?
--Could you batch the main oils and store it until someone asked for a specific SF and then add it at a later date?

Yes to both questions. Just trudge through the math.

--Could this work with Pine Tar as a SF?

Theoretically yes, but I'm not sure I would use pine tar as a superfatting ingredient.

--Would this same math hold for KOH as well as NaOH?

Yes it would.

 

[The Efficacious Gentleman]

I agree with the PT as SF! Might work as a soap/fake tan cross over

 

[MzMolly65]

--Could this work with Pine Tar as a SF?

Theoretically yes, but I'm not sure I would use pine tar as a superfatting ingredient.

Thanks everyone for your thoughts on my questions.

I questioned the possibility of Pine Tar for SF because I thought it might be more available for the skin to absorb, much like keeping EO's to the end so they are more available for skin contact.

That question played into the reason I asked about master batching. I don't want to waste an entire batch of oils just to have an experiment end poorly and without reference. If I make a master batch and then split it, adding different SF's, not only am I wasting less product but I have a frame of reference to test how each different SF looks and feels in the final soap product and how it works for the person using it.

I have a friend with some severe psoriasis and I'd like to send her several different samples to test and see which one she finds most soothing. I was thinking of a 100% OO base and one control sample superfatted with OO and then other samples superfatted with the various oils that are supposed to be good for psoriasis .. camelina, pine tar, mango, neem .. you get the point. I thought she might have a better chance of pinpointing which oils are actually helping, or if all the fancy oils are just a waste of time and money.

I could repeat the experiment twice, once for NaOH and once for KOH. Maybe even that could make the difference.