I recently made some soaps that started to crack after they had been cut. I already have a likely suspect, but I wanted to run it by you guys to see what you think.
Recently I ran out of isopropanol and because I didn't gel my soaps and I didn't want a thick coat of ash I decided to spritz with ethanol instead. It's only the latest soaps that were spritzed with ethanol that cracked. The cracks look kind of similar to the way high butter soaps look when they've been in use for a while. My guess is that since ethanol doesn't evaporate as quickly as isopropanol, the soaps got too wet, dried again, got too wet again and they ended up cracking because of this cycle, but that's really just a theory.
There's one batch that was only spritzed with ethanol and got severe cracking, while the other batch still had isopropanol the first day and a few days of ethanol after that (if I get ash, it often seems to come at day 3 for some reason). I think both soaps got the same amount of ethanol spritzed on them and mainly the age at which I started with ethanol differs (by one day, I made the soaps one day apart) The older soaps that were still spritzed with isopropanol are generally fine with just a few cracks here and there, while the latest soaps are full of cracks.
Recipe in case it matters: 20% coconut, 30% cocoa butter, 50% HO sunflower, the older soap had 30% lye conc. the one I made a day later had 33% lye concentration. Just before those soaps I made a few batches with a lot more cocoa and/or shea butter that didn't crack, so I'm sure it's not caused by the cocoa butter.
Recently I ran out of isopropanol and because I didn't gel my soaps and I didn't want a thick coat of ash I decided to spritz with ethanol instead. It's only the latest soaps that were spritzed with ethanol that cracked. The cracks look kind of similar to the way high butter soaps look when they've been in use for a while. My guess is that since ethanol doesn't evaporate as quickly as isopropanol, the soaps got too wet, dried again, got too wet again and they ended up cracking because of this cycle, but that's really just a theory.
There's one batch that was only spritzed with ethanol and got severe cracking, while the other batch still had isopropanol the first day and a few days of ethanol after that (if I get ash, it often seems to come at day 3 for some reason). I think both soaps got the same amount of ethanol spritzed on them and mainly the age at which I started with ethanol differs (by one day, I made the soaps one day apart) The older soaps that were still spritzed with isopropanol are generally fine with just a few cracks here and there, while the latest soaps are full of cracks.
Recipe in case it matters: 20% coconut, 30% cocoa butter, 50% HO sunflower, the older soap had 30% lye conc. the one I made a day later had 33% lye concentration. Just before those soaps I made a few batches with a lot more cocoa and/or shea butter that didn't crack, so I'm sure it's not caused by the cocoa butter.