3% Superfat - Oily film on top

[haidsta]

Hi there, After some feedback. I made up a 3% liquid soap and after a week there is an oily film on top, it mixes back in if you give it a shake and then separates again after a day. It feels like oil on your fingers. Paste was well cooked and had no zap. I'm hoping its just the 3% superfat oils floating to the top. What are your thoughts?

 

[DeeAnna]

Just a guess that the white layer might be low-solubility stearic and palmitic soaps from the cocoa butter and/or unsaponifiables from the jojoba. Or it could be superfat, although my mental picture of an overly superfatted or overly neutralized soap is the top layer looks more like curds in spoiled milk than a thin even layer like what's in your soap.

I made a LS with lard and this soap has a thin floating layer much like yours. I absolutely know it is not fatty acids or fats -- I wondered about that and added enough KOH to some of the diluted soap to make it intentionally lye heavy. The lye-heavy sample still had this thin white layer.

Irish Lass uses polysorbate 80 as an emulsifier for fragrances and stearic acid -- it might also work to emulsify the floating bits so your soap looks more consistent. Or you could remove this layer by skimming off the surface 1/4 inch after letting things settle for awhile. Or just embrace the soap as it is!

 

[haidsta]

Thanks for the feedback DeeAnna, very informative :think: I think I'll go with the skimming the layer off for the friends that I know will be a bit fussy and leave it for my own use.
I'm going to dilute some of the paste that has been sitting for two weeks and see if I have the same outcome. The paste itself has changed significantly and is a lovely amber colour.
Thanks again for your insights

 

[DeeAnna]

I think it's neat how LS paste can change with time. Mine usually look like yours and become more translucent.

When I made that lard-based LS paste, the undiluted paste was originally dull milk white but has changed to more of a pearly white.

 

[Zany_in_CO]

...3% liquid soap and after a week there is an oily film on top, it mixes back in if you give it a shake and then separates again after a day.

If the film formed at the top during dilution then not enough water was used. If you haven't diluted yet, then it's most likely unsaponified oil, i.e., 5% cocoa butter; 5% jojoba are likely suspects. Both olive oil and cocoa butter are high in unsaponifiables. Use cocoa butter at 2% max (for clear soap; more than that results in cloudy LS) Jojoba Oil at 2% max. (fatty alcohols in waxes can form a milky layer that floats to the top.)