Soap cracking after cutting

[penelopejane]

Thanks for your input @cmzaha I'm planning out a whole series of experiments to find the culprit before attempting another 'pretty' batch I really don't want to have this happen again..
I'll probably start with the exact same recipe as the shimmy soap and spritz a few bars with ethanol, a few with isopropanol and leave a few unspritzed to see if there's a difference and if I can replicate the cracks. After that I'll assess what test to do next, lowering the cocoa butter and/or changing the amount of citric acid. Maybe I should also assess gel vs no gel, since I didn't gel the cracked soaps..

Today I saw one crack that looked more like the shimmy cracks in one of the soaps that were spritzed with ethanol the past few days.
I also realized I never spritzed the end cuts of the shimmies with ethanol and they don't have those distinct cracks either. They do have a whole lot of ash that in some places has a crackling look, but I've seen that before with ashy soap and I think it looks different than the cracks on the shimmies. I'll try to take some pictures tomorrow.

I've started to doubt about the cocoa butter. The batch I was convinced I did with 40% cocoa was with 40% shea woops! That means the highest I've gone before these last (cracking) batches is 25% cocoa. There were no cracks in those soaps, but it was a different bag of cocoa butter. With the current bag I've only gone up to 20% cocoa with 30% shea and 20% coconut - also without cracking.

Olive oil is easy to source here and I often use it as a split. I'm still playing around with recipes to see what I like and it was purely a coincidence there wasn't any olive oil in the last few batches

I am sorry I couldn't help more.
There is a long history of using IPA in soapmaking. I don't know anyone who uses ethanol. I am not sure of the difference or the additives your ethanol has but I think comparing the two would be helpful.

Another way to stop ash is to use 33% lye concentration, soap warm and cover with plastic wrap after it has skimmed over. I put my soaps in a timber box as well and leave them to saponify and cool without checking them at all.

 

[szaza]

@penelopejane you've been very helpful! Also, good call on the additives in ethanol. I used up a small bit that I still had in a flask that didn't specify what it was denatured with. Probably diethylether or dibuthylether (it was a small bit I got from someone a while ago before I bought ethnol myself and I completely forgot about). It might be interesting to look at the difference between different types of ethanol as well.

Here are the pictures I promised a few days ago:

The crack that looks different to me in the batch of semicircle soaps. This is the only crack that looks this clear/well defined in the entire batch and this bar was spritzed with ethanol.
All the soaps from this batch are still soft and I have a feeling something is wrong with them. It's another first for me to have soaps not harden after a week.

These are the end cuts of the massively cracked shimmy:

The front is slightly ashy but still fine, the back has some cracks, though they look different to me than the cracks in the bars (which by the way have cracks all over on every side of every bar)

 

[szaza]

Hmm.. I've been looking around on the internet for isopropanol and only then I realized it's scarce at the moment, being one of the main ingredients in desinfectant (I knew, but somehow it didn't really sink in) I can actually get it, but now I'm doubting whether spraying soaps for aesthetic reasons is a responsible use of IPA in these times..
Maybe I should just up my lye concentration to 35% and hope for the best

 

[szaza]

A small update. The soap I did for the SMF May challenge used the same recipe as the shimmy, except it gelled and it didn't get cracks, so I think I can exclude citric acid and cocoa butter as likely culprits, which brings ethanol even more to the top of my list.
I finally got some IPA, so next time I make soap using this recipe I'll spray the main bars with IPA and the end bits with ethanol and see what happens.

 

[Jersey Girl]

A small update. The soap I did for the SMF May challenge used the same recipe as the shimmy, except it gelled and it didn't get cracks, so I think I can exclude citric acid and cocoa butter as likely culprits, which brings ethanol even more to the top of my list.
I finally got some IPA, so next time I make soap using this recipe I'll spray the main bars with IPA and the end bits with ethanol and see what happens.

I love your experimental curiosity and all you share with us!

 

[szaza]

That's so sweet @Jersey Girl I love experimenting with soap

 

[Jersey Girl]

@penelopejane you've been very helpful! Also, good call on the additives in ethanol. I used up a small bit that I still had in a flask that didn't specify what it was denatured with. Probably diethylether or dibuthylether (it was a small bit I got from someone a while ago before I bought ethnol myself and I completely forgot about). It might be interesting to look at the difference between different types of ethanol as well.

Here are the pictures I promised a few days ago:
View attachment 45695
The crack that looks different to me in the batch of semicircle soaps. This is the only crack that looks this clear/well defined in the entire batch and this bar was spritzed with ethanol.
All the soaps from this batch are still soft and I have a feeling something is wrong with them. It's another first for me to have soaps not harden after a week.

These are the end cuts of the massively cracked shimmy:
View attachment 45697
The front is slightly ashy but still fine, the back has some cracks, though they look different to me than the cracks in the bars (which by the way have cracks all over on every side of every bar)
View attachment 45696View attachment 45698

Dang...that’s a great shimmy. I’ve been meaning to try that technique.

 

[szaza]

Dang...that’s a great shimmy. I’ve been meaning to try that technique.

You should try! It's a fun one

 

[szaza]

I did a soap with 50% shea butter that didn't gel a week ago and decided to see if spritzing with different alcohols would make it behave differently. I spritzed the main bars with IPA and the and cuts with ethanol (2x/day for almost a week) Neither developed any cracks. Next time I do a 30% cocoa butter soap I'll try the same with those soaps to see if it was the combination of cocoa butter and ethanol that made the cracks. If not, I can't think of any explanation except the extremely low humidity we had in April.