Unsaponifiable amounts and lye

[soapgeek]

Hi,

I wonder if anyone can enlighten me please? I've been pondering superfats, but had a thought about the unsaponifiable amounts in oils... I hope this makes sense...

So, the SAP value relates to the amount of lye that it takes to convert a measurement of oil (eg 1g of olive oil) into soap... I know there are variances in the purity of NaOH, so if one used a SF value of 0 but a 97% pure NaOH, theoretically there will then be a 3% superfat...
What I'm wondering about now is the %age of unsaponifiables in an oil... say for example, using 100% shea butter, with 0 SF and 98% pure NaOH, resulting in a hidden 2% SF, if there is an unsaponifiable amount of oil/butter in excess of 2%, what happens to the excess lye if not all the oil can be saponified? Or would one need to find out the unsaponifiable amount as it relates to each oil, and reduce the lye accordingly?

 

[shunt2011]

There have been discussions on this in the past. unsaponifiables can vary in oils/butters from batch to batch from my understanding and different calculators have different SAP values as well. So, it's all getting as close as possible.

 

[DeeAnna]

Saponification values reported in the literature and used by the soap recipe calcs are not theoretical calculations based on 100% pure "ideal" fats. Sap values are based on real-life testing of real-life fat samples. This means the effects of unsaponifiable content in the fats are included in the reported sap values.

Yes, the soap recipe calcs use averaged sap values, so there is some potential for error if the sap value for a specific batch of fat is somewhat different than the average sap value for said fat.

But the only way you're going to know that for sure is if you measure the sap value of your actual fat. I don't know of any other way to determine a more accurate sap value than doing the chemical test procedure.

If you aren't willing to actually measure the sap value for your fats, then statistically you're better off using averaged sap values as the soap recipe calcs do, rather than guessing.

We've been talking about this in another thread -- Looking for Dish Soap bar recipe. -- start reading about Post #30.

 

[soapgeek]

Saponification values reported in the literature and used by the soap recipe calcs are not theoretical calculations based on 100% pure "ideal" fats. Sap values are based on real-life testing of real-life fat samples. This means the effects of unsaponifiable content in the fats are included in the reported sap values.

Yes, the soap recipe calcs use averaged sap values, so there is some potential for error if the sap value for a specific batch of fat is somewhat different than the average sap value for said fat.

But the only way you're going to know that for sure is if you measure the sap value of your actual fat. I don't know of any other way to determine a more accurate sap value than doing the chemical test procedure.

If you aren't willing to actually measure the sap value for your fats, then statistically you're better off using averaged sap values as the soap recipe calcs do, rather than guessing.

We've been talking about this in another thread -- Looking for Dish Soap bar recipe. -- start reading about Post #30.

Thanks, I think maybe that's what I was trying to get at, that there's a tolerance in each Sap value to allow for unsaponifiable content of that oil