White layer formed on soap bar

[DrewsSoaps]

Hey, I’m newer to Bar soap making, very used to liquid soap, and I have a question about a new recipe I used, well, the results of the new recipe. So the question is about a white outer layer being formed on the soap bar, however the only parts of the soap that has the white layer are parts that were in direct contact with the circular silicone mold that I used. I’ve made more than 5 batches of soap with these molds, and each time I never had a white layer formed anywhere on the soap bar. when I washed the soap molds prior to pouring, I boiled them in a 1% alconox powdered detergent solution with a little dawn. I mean, yeah the soap molds felt ever so slightly slick after I washed them off, but I attributed it to them just being wet. This was an experimental batch as well, so I let a few GMP down. I’m just wondering if this is something anyone is familiar with, or if it could be most likely attributed to the silicone molds not being properly cleaned. I know that’s a hard Q to ask because you didn’t see the molds, but they were clean enough for me to use, so they weren’t dirty by any means. I am going to scrape some of the white outer layer off into a beaker with water and test the pH to see if it’s something alkaline, I’ll

Also make a control to test with the outer soap layer that didn’t have contact with the silicone tomorrow and I’ll post the results. I’m just trying to do this quickly because I wanna get a bigger HP soap batch ready to be able to send the people affected by the hurricane in NC. Thanks, pics and recipe

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[bookworm42]

My guess is that it's soap ash. Was the white stuff there when you unmolded or did it form after?

Soap ash is purely cosmetic and should come off with a little water or steam. It's caused by lye reacting to water in the air.
Soap ash can be tricky. You can make 2 batches not change anything but one gets ash and the other doesn't.

 

[AliOop]

Yup, looks like soda ash to me, as well.

 

[KiwiMoose]

Are you sure it's on the sides that contacted the silicone? It looks like it's just on one side to me - usually the side that is exposed to the air ( i.e. not touching the silicone).

Any way - it's almost certainly soda ash and sometimes it just happens. It could be that you didn't gel the soap - but I sometimes still get it on gelled soap. Some recipes might be more prone to soda ash than others.

If you ascertain that it is indeed the side exposed to the air, then easiest way to stop it from happening is to cover the soap as soon as it's poured. If using individual/cavity molds such as this, I usually just tear off a sheet of baking paper and sit it on top of the mold (it needs to touch/stick to the top of the soap), then place a chopping board or similar on top of that. Leave them in the molds a little longer than necessary (maybe three or four days) to maximise their time without air exposure.

 

[Ekuzo]

I agree with the posts above, looks like soda ash to me as well. KiwiMoose gave a very detailed reply, you can't go wrong with that.

I've also heard you can soap hotter and pour at a thicker trace, as well as discount your liquid amount to minimize this effect