Mixing pigments w/ glycerin - need preservative?

[jblaney]

I mixed some pigments a while back, maybe 4 months ago, with glycerin. I used one the other day and it smelled bad. I think it was a neon color I bought from TKB Trading. They don't all smell, but I was wondering if I should put some kind of preservative in them so they last longer. Can pigments and glycerin go bad?

Thank you.

 

[Genny]

Yes glycerin + mica can go bad. There are some suppliers that add preservatives to them because of that.

 

[jblaney]

Thanks Genny. That's what I will do too.

 

[HaveAHeartRescue]

I was wondering that as well...I do recall a few posts where some were saying that Vit E was/was not a preservative. I know that in my dog's food...Vit E (tocopherol) is the preservative. So what's the thing to use?

 

[Genny]

Using vitamin e even in food as the only preservative is not the best preservative for long lasting items. I've seen some dog food that only has vitamin e as the only preservative as well. We buy dog food in small amounts though because our dog is little & doesn't go through a lot.

But as far as what preservatives you can use, Germaben, Optiphen, really any preservative that you want that won't be deactivated by any of the ingredients in your colorants or by glycerin.

 

[HaveAHeartRescue]

That makes sense for the short term VS long term. Very good point. Now if someone were to use regular spices and herbs instead of Mica's...would they still need to use a preserve? How long would a soap with spice or herbs last without it?

 

[Genny]

The preservative is just for in storing the colorants for long term. If you used spices & herbs, I'd say use a preservative as well unless you can guarantee that your work area, packaging and equipment is completely sanitary.

But if you're just making up a small batch of colorants to use right before soaping, there's no need to add a preservative.