Glycerine soap vs CP

[Gypsybaron]

Hi all

I have been making Glycerine soap for about 2 years now, using Lauric and Stearic acid in "powder" form, and the rest is all liquid (Glycerine, lye solution in filtered water, SLES70, TEA, Sorbitol, Glycol). I then pour it into cylindrical molds, and this I either cut into "disks" for my guest house clients, or re-melt it and pour it into other molds (basically, I make my own M&P soap ) I make uncolored (Plain, for customers who want to color and flavor it themselves), pink (Rose), green (Lemongrass), purple (Lavender) and opaque white (Sandalwood) soap tubes. I also do other flavors on request, but these are my best sellers. However, recently I noticed that the soap is slightly more brown in color than previously - does anybody know why it happens?

What I like about the recipe I am using, is the fact that there is no "curing period" like with CP soaps - as soon as the soap tubes have cooled down, the soap is solid and can be used immediately - I have been using my own soap since I started making it, whenever I use store bought soap I develop dry skin but with my homemade soap it all disappears within a day or two - thus I am doing the dermatological tests on myself! The "browner" soap feels just the same as the older, clearer soap, it just looks a little less appealing.

My only gripe with my recipe is - the soap doesn't last very long! Probably because I like the way it lathers and cleans

 

[Yooper]

I can think of only two things that would cause it to turn brown. First, because glycerin is a humectant, pulling moisture out of the air (that's why your skin loves it, it holds in moisture), it could turn brown , not really "going bad" but not being as fresh as it was.

Also, oxidation could be a possibility I guess- it happens to things like beer, but I don't know about soap.

Also, if you use any fragrance oils, vanilla is infamous for turning brown in soap.

 

[ChemicalPyros]

I am aware that the oxidized SLES70 gives a brownish yellow color, so if you have changed suppliers recently check with them.
sometimes the sorbitol will give a brown color if heated at high temperatures, so check the equipment that you are using they may need recalibration.