yellow spots

catikit · Nov 17, 2011

Hi there,
I've noticed that when i leave soaps to cure for a long time (e.g. a couple of months) they seem to develop yellow spots on them in patches. What could be the cause of this and how can i avoid it? I think (but am not totally sure) that its exclusive to the soaps that have shea butter in......

fiddletree · Nov 17, 2011

Sounds like DOS. It happens when your soap goes rancid. Won't hurt you, but makes the soap not smell or look so nice. Someone else can chime in who has more experience with DOS (I'm lucky and have only ever found one bar of soap with a little bit of it it), but generally it occurs when you use unstable oils (like hempseed), rancid oils, if there is too much humidity, or even certain EOs or FOs can promote it.

I've not heard of this being a problem with shea.... I use it up to 30% in many of my soaps and they've never gotten DOS, but there are always many factors at play. Is that the only differing ingredient in the bars with DOS?

Oh, also, separate out your bars with DOS because it can spread!! Don't ask me how, but maybe it's like one bad apple in a barrel make them all go immediately....

lsg · Nov 17, 2011

Soaps made with Canola and sunflower oil can develop DOS. I don't use canola and always use high oleic sunflower oil, when I use sunflower oil. I haven't had any problems with DOS since I started blending in a little Vit. E with my oils before adding the lye solution.

http://www.soapnaturally.org/DOS.html

Bigmoose · Nov 17, 2011

It could be from a number of things. The types of oils you are using, the water you use, even your drying rack can effect this. I had an issue with dos a few years back and looked at all the oils I was using and started adding a small amount of vitamin e, switched to using distilled water, and dry my soaps on coated drying racks and have not seen dos since then.

Bruce