Mashed potatoes or Vaseline?

[Tara_H]

This may be a stupid question but hot process soaping is not usually my thing. The only recipe I've done HP before is for liquid soap and it specifies that the paste should look like Vaseline when finished.

Yesterday I was making transparent soap according to How to make transparent soap - Curious Soapmaker. she doesn't specify what it should look like so I assumed the Vaseline stage I was familiar with. However, around the transition from potatoes to Vaseline it started getting very dry and incredibly hard to move - I actually cracked the silicone on a new silicone spatula trying to mix it around! I ended up adding probably half a cup extra distilled water just to get it soft enough to completely cook to the Vaseline stage. Then in the dissolving phase it took a bunch more alcohol than the recipe calls for. Again I went with what I knew from the liquid soap in terms of dissolving, aiming to get it to a point where it was homogeneous.

This morning I figured I should learn more about HP since I intend to make another batch. The tutorial below goes only to the potatoes stage and calls it good, and I feel like that would make all the following steps much easier to deal with.
(Unfortunately I don't have any reliable indicator, which would probably help a lot here?)
https://www.soapqueen.com/bath-and-body-tutorials/cold-process-soap/marbled-clay-hot-process-soap/
Is there a significant difference in what's going on in these two phases? Or is it primarily visual and not a sign of a meaningful change?

 

[Lin19687]

I've not tried that kind so can't really help that much but honestly it seems cheaper to just buy clear M&P

 

[Tara_H]

I've not tried that kind so can't really help that much but honestly it seems cheaper to just buy clear M&P

Thanks for the reply! To be honest it's more about the learning process and experimenting to see what I can do and how it all works rather than just having the result.

I was one of those annoying kids who spent a lot of time disassembling things to figure out how they worked... Sometimes I even managed to put them back together again!

 

[DeeAnna]

It sounds like you cooked too much water out.

I don't think regular hot process soap has to get to the "vaseline" texture to be properly saponified, but I know "it's a thing" for many soap makers to get hot process soap to that stage. The soap will have a better chance of getting that texture if you minimize evaporation as much as possible. Some soap makers will even cover the soap pot with plastic food wrap for a really tight seal.

When using alcohol for the solvent, minimizing evaporation is even more important, not only to get the soap transparent(ish) but also to control the expense and the fire hazard.

 

[Tara_H]

It sounds like you cooked too much water out.

I agree, that's totally consistent with what I was seeing. I should have mentioned in the first post but I made a much smaller quantity also, which I presume would contribute to faster evaporation.

I don't think regular hot process soap has to get to the "vaseline" texture to be properly saponified

Great, thanks! This is the critical piece of information, I guess.

I was actually very happy with the outcome finally; I left it in the fridge overnight and by this morning it was a solid and slightly jelly-like texture that I could cut easily with my wire cutter. I have a project in mind that I'll need a few batches for, though, so if I can start diluting once it's at 'mashed potatoes' then it will save me a lot of hassle. I may try that later on today and see how it compares for transparency.

 

[RDak]

It sounds like you cooked too much water out.

I don't think regular hot process soap has to get to the "vaseline" texture to be properly saponified, but I know "it's a thing" for many soap makers to get hot process soap to that stage. The soap will have a better chance of getting that texture if you minimize evaporation as much as possible. Some soap makers will even cover the soap pot with plastic food wrap for a really tight seal.

When using alcohol for the solvent, minimizing evaporation is even more important, not only to get the soap transparent(ish) but also to control the expense and the fire hazard.

Most definitely THIS!

Go for the mashed potatoes look. And it doesn't have to be a real "fluffy" mashed potatoes look either. You'll get the hang of it once you do a few batches. But DeAnna is definitely right IMHO........go for the mashed potatoes look.

Vaseline texture is going too far IMHO.

 

[Tara_H]

Tried it again today and it was so much better!

I added the alcohol and glycerine when it looked like this instead of waiting for any hints of Vaseline:


It broke up very quickly into small pieces which dissolved completely with minimal effort, I didn't even bother turning up the heat for the dissolving phase.


The final result was still perfectly transparent, but it set a lot quicker than the last batch; maybe 3 or 4 hours to get to a fairly jellied point. @DeeAnna, @RDak, thanks so much for the input on this!

 

[AliOop]

Nice job! I've never made M&P, but back in my regular HP soap days, I definitely stopped at Vaseline. The soap got too dry, chunky, and difficult to mold if it went to mashed potatoes. I didn't bother checking for zap since soap will always continue saponifying on its own, and I never plan to use it right away anyway.

In fact, I had fun experimenting with various lengths of cook. Cooking it for less time had no discernible effect on the end result, except that it was much smoother and didn't end up with the typical "rustic" HP look. Still not as smooth as CP, but much more to my liking.