Odd look to my soap

[Sraymoure]

I’m following single oil soap recipes in Scientific Soapmaking. My olive oil soap was in a smooth mold but have a very bumpy surface, unlike anything I’ve seen. Any idea what happened? It’s on the bottom and sides but the top is smooth. It was very thinn when I poured it, then was in an oven at 140 degrees F for 4 hours

Used lye masterbatch at 1:1 with no additional water.

Any help appreciated!

 

[Obsidian]

Thats what we call silicone rash. It happens when soap gets too hot in a silicone mold. When you oven process your soap, you do not leave the oven on.

Next time heat the oven to 170 F, turn it off then place your soap inside.
You just want to help it stay warm, not cook it.

Its perfectly safe, just odd looking. I have to say, thats some of the coolest rash I've seen

 

[cmzaha]

at you Obsidian. You would think it is a cool rash!! But yes, Obsidian is correct that it is silicone rash, and she is also correct as to not cooking it in the oven.

 

[Sraymoure]

Thats what we call silicone rash. It happens when soap gets too hot in a silicone mold. When you oven process your soap, you do not leave the oven on.

Next time heat the oven to 170 F, turn it off then place your soap inside.
You just want to help it stay warm, not cook it.

Its perfectly safe, just odd looking. I have to say, thats some of the coolest rash I've seen

Thank you !!! Reminds me of something I saw years ago as an enlarged microscope picture. I followed the directions in the book since it was a one bar recipe, but will not repeat!

Thanks again

 

[Teresa408]

Someone on another thread was describing a soap as “spongy” and this soap would fit that description, at least in appearance! I’ve fallen victim to the silicon rash myself, I was just a little too enthusiastic to make sure my soap gelled.

 

[earlene]

One thing to keep in mind is that ovens are more likely to NOT heat to the temperature you expect and can often be much hotter (or cooler) than you think based on your setting. They are actually notorious for that. Which is one reason why restaurants get their ovens calibrated periodically. But that's beside the point, but pertinent.

My response to this diliemna is that I use an oven thermometer to read the actual temperature of my oven. I heat my oven to the lowest setting, turn it off and don't put the soap in unless the oven thermometer reads below 150°F. Then I put the soap inside, cover it, close the door and leave it. I usually leave my soap in the closed oven for a few hours before checking it again.

 

[Atihcnoc]

I heat my oven to the lowest setting, turn it off and don't put the soap in unless the oven thermometer reads below 150°F. Then I put the soap inside, cover it, close the door and leave it. I usually leave my soap in the closed oven for a few hours before checking it again.

I do the same but leave the oven light on for 2 hours, turn off and leave in the oven overnight uncovered.

 

[Sraymoure]

Thanks everyone. I was just doing as instructed in the directions. My oven has always been very accurate but it is getting on in years and I may need to check the accuracy. Soaping is a journey. I really appreciate all the help and feedback from all on this forum.

 

[Rune]

You poured at a very thin trace. I think that is the reason for the extreme silicone rash. Spending a long time in the oven, perhaps at over 140 degrees since ovens might go way, way higher than you think when setting it to a low temperature, may have made it even worse. Or made it cool! I really like it!

According to a post on Auntie Clara's blog (link at the bottom), to reduce the chances for silicone rash you should pour at a thicker trace, or wait until the soap thickens in the mold before you pop it in the oven. I know that can be slightly hard with the slow tracing olive oil, but just run the sticblender on full speed ahead, non stop, and it will come to trace before you know it.

Here you can see Auntie Claras experiments with CPOP problems like silicone rash, alien brains, overheating, and how to avoid them:

https://auntieclaras.com/2015/06/overheating-soap/