Potassium soap superfat

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Baqn

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Does anyone knows what might mean that 3% SF in potassium soap is equal to 10% SF in sodium soap? Is it correct?
 

ResolvableOwl

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That sounds ambiguous at best. More context is needed in any case.

It might simply mean that liquid (K) soap is less concentrated than solid (Na) soap, so that, based on total mass (which is an unusual measure for good reasons), the absolute SF numbers are lower with K than Na soaps. These values will become more similar once converted to relative (= ppo) numbers.

It also somewhat sounds like the SF upper limits at which (initially) saponification appears to be successful (these limits are indeed much tighter with K soap). At these SF values, the absence of separation/turbidity/DOS/rancidity is a matter of luck (and/or advanced techniques).

tl;dr: This statement might be based on useful advice. But it is of little value as long as the circumstances are unclear.
 

Baqn

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This statement is not for particular soap or recipe. It was written as basic statement.

Yes it might be connected with concentration.
 

DeeAnna

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A 3% lye discount for KOH is the same as a 3% lye discount for NaOH. In either case you end up with the same amount of superfat.

The purity of the alkali does affect the lye discount so if you want the most accurate results, you'd want to incorporate a correction for purity. That's not a difficult correction to make even if you have to do it by hand, unless you're really uncomfortable with math.

As defined, lye discount and superfat are not based on the water content, only on the fat and alkali. A 3% superfat in a diluted liquid soap is the same as a 3% superfat in KOH paste is the same as a 3% superfat in bar soap.

This is the basic info you wanted -- if you want the full math and chemistry background, let me know.
 
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