Dreaded DOS! Connected to gel?

[SudsSanity]

Hello soap addicts!
I have been making CP soap for approx 1yr. I have a stable base recipe and modify that based on my goal in the final product.
My question is - I created 2 batches, used the same recipe (different FO). I gelled one, and did not gel the other... Now- 6 weeks later, 1 of the bars from the gelled batch has 1 very faint DOS.
I usually never gel my soap..(and have never seen DOS on my soap) This specific bar has a pink in it that I wanted to have gel..
Does anybody think the gel phase could contribute to DOS?

 

[IrishLass]

Are you sure it's DOS and not a bit of leaking FO? I ask because that can happen at times.

DOS is not caused by gel. According to Dr. Kevin Dunn in his book, 'Scientific Soapmaking', DOS is caused by oxidation of unsaturated fatty acids in the presence of trace metals, and it can be controlled by either reducing the percentage of unsaturated oils in one's formula (those that are high in linoleic and linolenic such as canola and soy for example, etc..), adding an anti-oxidant such as ROE to one's oils, or including a small amount of chelating agent such as tetrasodium EDTA in one's batch.

As an aside, I've heard a few anecdotal reports of certain EOs contributing to DOS, such as lavender, for example, but I'm not sure why that would be (maybe trace metal contamination of some sort?). Hopefully someone with more knowledge about that will chime in on that.


IrishLass

 

[DeeAnna]

Oxidized (old) lavender essential oil definitely can trigger DOS.

 

[Seawolfe]

That picture is really low resolution, is there something on the bars? They look like little pine cones?

 

[galaxyMLP]

I recognized this soap from a few weeks ago on the Facebook mica group I'm on. I got some higher resolution pics off of it. Hope it's OK, I'm posting them. These obviously don't have the spot but at least you can see the detail. They are quite lovely.

 

[SudsSanity]

Sorry about the pic resolution.
Yes, SW ~ there are MP roses attached to the bars. The scent is Love Spell.

Irish Lass ~ great information, thanks for the name of the book: (I'm checking Amazon for it now). I'm sure it's not leaking FO.. I am actually using the bar now.. I cut it in half where the DOS was; no liquid inside, no heavy lye pockets, etc.
just. One. Dreaded. Orange. Spot.

 

[SudsSanity]

LOL! Thanks, Galaxy!
All of the other bars are good... Just the one.. Just wondering, since the only difference between the gel and non gel batches are: fragrance, temperature, and colors.
All of my bars cure in the same area.

 

[galaxyMLP]

Is it possible that there was contact with a metallic surface with that one bar? Metals can cause free fatty acids to oxidize more rapidly. I would not guess that gel would effect DOS prevalence. However, how do you usually prevent gel, and in this case, how did you encourage it? It may have something to do with that and not gelling the soap itself.

 

[SudsSanity]

Galaxy ~ I soap at room temp (lye solution melts butters). Usually, batches go directly into fridge after pouring. For this batch, I left out and insulated... Perfect gel throughout.

Come to think of it, this one bar was closest to another batch I made with vanilla, while it was turning brown... Hmmmm? Think the "vanilla browning effect" could have "jumped bars".

 

[galaxyMLP]

If they touched, absolutely. Vanilla FO discoloration actually bleeds. It does not stay "crisp" b/c the fragrance itself can migrate. If they were touching for about a week I would say that is probably your issue. Especially since its only on one bar and youve never seen it before!

 

[navigator9]

I would hang onto that bar to see if more "DOS" spots appear. I don't think I've ever had a soap with just one spot on it. On the few batches of mine that have had DOS, more spots appeared over time. Also, does the spot have an "off" smell, like rancid oil? With just one spot on one bar, I'd reserve judgement. There could be other causes.