White powder on top

[Kenaslan]

Okay, I have a question for the chemists here. Sometimes there is a white residue and sometimes there is no residue on top of the soaps. I know it is something that reacts to the air, else it would be on all sides, however it is only on the top that is exposed to air for the pour. The same formula except different fragrances, some have some do not??????? Can someone tell me what it is and why?

 

[jcandleattic]

It's what's called in the soaping world as Ash.
As far as I know there has never really been a true diffinitive reason as to why sometimes it happens and sometimes it doesnt.
I've had batches that are exactly the same - down to the same temp in the room and one batch had ash on it and one batch didn't.

 

[Cristy]

Someone told me that you can polish that ash right off with a cheese cloth or a panty hose....don't know if it works or not but thought I'd mention it.

 

[Soapy Gurl]

The only soap I get the dreaded ash on is Lavender EO. Which I put lavender buds on so I can't get it off. But wait, actually my last batch had no buds and I did a swirl and I had no ash. It was my first lavender CPOP batch. I have never been able to figure out why I got it. :?

 

[Fragola]

There is an article floating around which explains that not all white residue is ash.

From what I remember, true ash comes from lye reacting to air. It is formed during the first days for CP soap, only on the surface and can be easily washed off. Covering the mold helps preventing it.

That being said, I also got "ash" recently on half of batch where I honestly don't know what's different from the other half. And much later than the first few days.

 

[judymoody]

If you spray 91% isopropyl alcohol on the exposed portion of your soap with a spritz bottle right after pour, it inhibits ash.

 

[xyxoxy]

I mostly use a tube mold (PVC) so the ash I get on top is easily cut off and the rest of the batch is fine. However some people use plastic wrap to cover the tops and that supposedly helps prevent ash.

 

[jcandleattic]

I mostly use a tube mold (PVC) so the ash I get on top is easily cut off and the rest of the batch is fine. However some people use plastic wrap to cover the tops and that supposedly helps prevent ash.

I do this, I still get ash on some of my soaps.
Most of the time - since it's just an aesthetic problem - I just let it occur. Sometimes it even inhances the look of the soaps.

 

[IrishLass]

There is an article floating around which explains that not all white residue is ash.

True. Dr. Kevin Dunn addresses this issue in his book Scientific Soapmaking. If you click on the following link, you can read what he wrote about ash:

http://cavemanchemistry.com/HsmgJojoba2011.pdf


IrishLass

 

[AmyW]

There is an article floating around which explains that not all white residue is ash.

True. Dr. Kevin Dunn addresses this issue in his book Scientific Soapmaking. If you click on the following link, you can read what he wrote about ash:

http://cavemanchemistry.com/HsmgJojoba2011.pdf


IrishLass

I need that book. That is a great link, thanks.

 

[Pretty n Plain]

If you spray 91% isopropyl alcohol on the exposed portion of your soap with a spritz bottle right after pour, it inhibits ash.

Judy, thats a good suggestion, I put my soap straight into the freezer after pouring, i've never had a problem with partial gel this way except recently when I took my time getting it tucked away to bed. However I do have a huge problem with ash (I think I was reading somewhere on here today it had something to do with the soap cooling too quickly.)
Anyways, I found if I sprayed the isopropyl alcohol on when I saw the ash it disappered. Next time I will try your suggestion and see how it goes.