Same batches - but some bottle separating

[Susie]

Too high of a superfat. Best as I can figure, you had somewhere in the 4.5% superfat range. Superfat will always gather in the top portion of paste. So when you go to use a paste that has sat a while, the higher superfat is in the top portion. Don't ask me how that happens in that thick of a paste, but every batch of paste I have let sit for a while with any superfat higher than 3%, it always happens.

If I am going to let paste sit for a while before dilution, I will usually go ahead and divide it while it is still very warm to the touch. This helps keep this from happening for me.

I am pretty sure the polysorbate 80 should have helped with the separation, but I have never used it, so I am going to have to let more experienced folks help you there.

 

[sapuncic]

Thank you Susie for the reply as well as for the tip for the paste! Next time I will do as per your advice or if I let it sit longer then I will mix the paste thoroughly before dividing for dilution.
Although I am pretty sure I randomly scooped the paste out (top and bottom and around the pot).
I was afraid it might be the superfat, although I intended to have 0% superfat. The thing is that Summerbee calc was giving 101.7 g KOH for 500 g of OO & 0% superfat, but my KOH vendor told me that the KOH purity is 95% and so I reduced KOH to 100 g since summerbee calculates for 90% KOH purity.
Seems like my KOH might be closer to 90% and not 95% as I was told :-x

 

[Susie]

Yeah, I never change the amount of KOH(or NaOH) that the calculators tell me to use based on what I think or the vendor thinks the purity percentage is. I have yet to have any problems related to KOH purity.

 

[sapuncic]

Yeah...I will not do it again definitely. Thanks for sharing your experience! :smile:

I am not sure what to do with the one that separated....to discard the top layer and use the rest or to add some Polysorbate80.... or maybe add some dissolved KOH, cook a bit and see what would happen... :?:

 

[sapuncic]

I did some heavy thinking these days regarding soap separation....

Is it possible that in the case of superfated soap a more diluted soap would be more likely to separate since there will be an increased difference in viscosity/density between soap (bottom layer) and oil portion (top layer), compared to less diluted one where soap and oil portion might have close densities and therefore oil portion stays suspended in the soap... :?:

Any thoughts on this theory?

 

[Susie]

I have not had the years of experience making liquid soap that some of these folks have, so I may not be the best person to give an opinion here. Hopefully, a few of them will step in and answer that.

My experience has been that three things cause separation only: Too high superfat, certain oils, some FO/EOs. I am highly diluting liquid soaps for foamer bottles, and have had no problem with separation.

My theory on the oils that cause separation are that the extraction methods might be different or someone has added other oils to them. They seem to be inconsistent on whether they cause separation or not. I have become extra careful to note the brand of oil on every recipe. That way if I have problems, I can easily see if it is tracked to one manufacturer or not. I may never use all this information, but better to have it and not need it than need it and not have it.(I need to get all of this on computer so searching it will be easier!)

 

[FGOriold]

I did some heavy thinking these days regarding soap separation....

Is it possible that in the case of superfated soap a more diluted soap would be more likely to separate since there will be an increased difference in viscosity/density between soap (bottom layer) and oil portion (top layer), compared to less diluted one where soap and oil portion might have close densities and therefore oil portion stays suspended in the soap... :?:

Any thoughts on this theory?

Here is an interesting read on that subject that might be helpful. It is more about gravity than density though:

http://swiftcraftymonkey.blogspot.com/2014/12/weekday-wonderings-using-polysorbates.html

 

[DeeAnna]

Specific gravity is basically density of any material divided by the density of a "reference" material. Usually the reference material is water. Here are two examples of the same oil and how you would end up with the same specific gravity number from density in two different kinds of units (grams/milliliter and pounds/cubic foot):

Water density = 1 g / mL
Oil density = 0.92 g / mL

Specific gravity of oil = Oil density / Water density = 0.92 / 1 = 0.92

Water density = 62.4 lb / cubic foot
Oil density = 57.41 lb / cubic foot

Specific gravity of oil = Oil density / Water density = 57.41 / 62.4 = 0.92

***

"...Is it possible that in the case of superfated soap a more diluted soap would be more likely to separate since there will be an increased difference in viscosity/density between soap (bottom layer) and oil portion (top layer), compared to less diluted one where soap and oil portion might have close densities and therefore oil portion stays suspended in the soap..."

I want to say that it's important to not confuse viscosity (syrupy-ness or watery-ness) with density. They can interact with each other, but they are quite different properties.

You can have two materials with the SAME density (weight / volume) and any viscosity. The two won't separate if mixed together. You can have two materials with DIFFERENT densities and any viscosity, and the two will eventually separate if mixed together.

What is affected by viscosity is the rate (speed) of separation. If the primary liquid is viscous and the density difference between the liquids is small, the rate of separation will be very slow. An example would be a soap paste (very viscous!!!) containing too much superfat. If the primary liquid has a thin viscosity and the density difference is large, the separation will be fast (diluted LS with too much superfat).