silicone blisters

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penelopejane

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

Auntie Clara has an expose on silicone blisters which she says are caused but the soap batter touching too-hot silicone.

She also says that batter poured at a thicker trace or batter left to sit for a while (so set a bit) before it goes into a warm (not hot) oven seems to overcome the bubbles.

Very interesting article with lots of pictures!
 

IrishLass

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Leave it to my soap to contradict her explanations, wouldn't you know it. ;) LOL I pour at thick trace about 98% of the time, my filled soap mold sits on my counter for about 20 minutes or so while I clean up, my oven is barely warm when I put my soap in it (110F), and I turn the oven off as soon as it's in there. If you ask me, I'm convinced that the type of silicone has more to do with it than anything else. I base my hypothesis on the fact that my Woodfield's silicone molds never give me blisters, but my ED silicone molds always do. The type of silicone material they each are made from is very different from each other, both in appearance and feel.


IrishLass :)
 

penelopejane

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Darn it Irish Lass. I thought the great Auntie C had solved a problem for us!

I do all those things you listed (because I listened to you) except I only go to 100 * F and I don't get the spots (touch wood) Although I do, generally, stick my mix straight into the oven.

So it must be the molds. I use BB molds but also one food safe silicone muffin mold I stole from the kitchen.
 

CaraBou

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I'm banking IL is at least partially right. But I'm still figuring out what exactly sets off the ED molds, as I've had mixed results. Lately I've been using my smaller CC molds (which never blister). But just this past weekend I soaped in both my bigger white and red ED silicone loaf molds; both had some blisters, but only the red mold was significant (even then it was patchy). I actually thought it would be the other way around because I accidentally put the white loaf in a preheated (170 F) oven without first turning it off. I noticed that omission about 1/2 hour later, then promptly turned off the oven and cracked the door. About 10 minutes later I popped the red mold the same oven, which had by then cooled significantly. I did not use a thermometer to detect actual temps; instead went by skin feel.

The two batches were largely the same with the following differences (in my perceived order of importance):
insulation: the white mold was braced by a thin, partial plywood support frame (some of the mold was bare), whereas the red mold was taped shut in the original tight fitting cardboard box that it came in;​
Base color: the white mold soap was yellow from beta carotene tinted coconut oil, whereas the red mold had normal CO for a natural base color​
Other oils: were exactly the same except the white mold had 10% avocado oil whereas the red mold had 10% olive oil​
Of those variables I think the insulation is the most significant culprit, with the FO following closely.

The blister results suggest the red mold overheated in the cardboard support despite the cooler oven temps, compared to the white mold.

I will admit that I have had more blisters in some previous batches in the white mold; not sure about particulars like insulation. I also know I have NOT gotten blisters in any of the few other red mold batches I've made. Also, I might as well add that red mold did not bleed onto the natural base colored soap of this batch, tho that did happen once before. I have no speculation on the difference in bleeding. Sorry for the lengthy post!
 

cmzaha

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Leave it to my soap to contradict her explanations, wouldn't you know it. ;) LOL I pour at thick trace about 98% of the time, my filled soap mold sits on my counter for about 20 minutes or so while I clean up, my oven is barely warm when I put my soap in it (110F), and I turn the oven off as soon as it's in there. If you ask me, I'm convinced that the type of silicone has more to do with it than anything else. I base my hypothesis on the fact that my Woodfield's silicone molds never give me blisters, but my ED silicone molds always do. The type of silicone material they each are made from is very different from each other, both in appearance and feel.


IrishLass :)
I would assume silicone mixtures vary quite a bit. We used to make up to 10' urethane molds and my husband went through a lot of grief until our supplier's chemist finally got it right at least until our partner wanted green instead of gray. What a nightmare that was when sound walls were poured and the green came off onto the cement. I would say ED needs to work with the chemist a bit more. Just small changes can make a huge difference
 

navigator9

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We've been round and round this problem and never seem to get to the bottom of it. I'm one of those who always CPOPs and never gets blisters. Several different mold suppliers...no blisters. Has Kevin Dunn ever addressed this problem? I wonder if there's some way of getting in touch with him to see if he'd be interested in addressing this issue. And penelopejane, I have one of those molds, too. I believe it's actually a cupcake mold, it's red, and yes it bleeds terribly, but I always CPOP and thought heat was the issue.
 

elmtree1748

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I have the Ed molds and I never get blisters. I also make about 8-10 loaves at a time so they sit for a bit and wait for me to finish before I put them in the oven. They are mid gel by the time they go in. Not sure what that means.
 

KristaY

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So here's another twist to throw into the mix. Primarily I use BB silicone loaf molds which give me blisters more times than not. I rarely CPOP, just insulate with towels. I was wrapping a batch the other day and noticed minor blisters on a loaf with partial gel! Yep, blisters and partial gel. VERY weird indeed. I was thinking I was insulating too much, creating too much heat, so started to insulate less. Then I saw the blisters and partial gel so that theory is out the window. Now I wonder if I should just stick with my wood loaf molds or invest in new silicone molds. I baffled at this point.....
 

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