Suspecting metal rack causing DOS

[SoapSap]

I have had two incidents of DOS developing recently. The first time I decided it was most likely related to the grape seed oil.

Now I just discovered a second batch that I made August 31 developing DOS. No grape seed oil was used in this formula. The only two oils I think would be suspect are Avocado oil and Canola Oil.

I also used English Rose Fragrance Oil.

The soap does not smell off in any way, and when I shave off the surface, the DOS appears to be on the surface only - at least so far.

The DOS is only on the bottom of the soap and it is appearing in the exact part of the soap that was in contact with the racks they sat on during initial curing. I used my baking racks to do this and I am wondering if the metal racks reacted with the soap and caused DOS to start. I would not suspect this except for the DOS appearing exactly on the lightly imprinted rack lines that and no where else and as I stated, so far not inside the soap.

Does anyone have any similar experience. And does my theory sound like a reasonably cause?

I have shaved off all the DOS. If it is not caused by spoiled oil, and it has not penetrated inside, do you think the soap is salvaged?

 

[Obsidian]

Yes, the metal rack is most likely the cause. Can you cover the rack with something like parchment paper or plastic cross stitch sheeting? The soap is usable, you don't even have to cut off the DOS unless it smells bad.

 

[new12soap]

Agreed, raw or curing soaps should not be in contact with metal.

Grapeseed oil has a short shelf life, and canola oil is very prone to DOS, although some do use it without a problem. Personally I don't think it brings anything great to the soap that makes it worth it to me, but YMMV.

 

[SoapSap]

This is the DOS EXPLANATION I am moving toward.

Regarding the Canola oil, I used it because I was doing some swirl designs and canola is supposed to slow down trace time. Also Canola is listed as having a long shelf life, so I thought it would be an oil also lesser inclined to develop DOS. The canola oil was not the major percentage of oil either.

I know now though that I will never again cure on a metal rack! I am going to get some plastic canvas to cover them. I like using something that encourages air flow all around the surfaces.