Lemon Poppy Soap Darkness

[stanekster]

Hi,
This has a been a problem for some time now. Most people do not care (probably because they did not see soap when I was cutting it), but it bothers the heck out of me. So I make a soap and it turns out really nice. I cut it the next day to see glorious yellow color....thinking this time will be different. And then sometime between 3-5 days later the darkness comes....and it smites down my soap. So instead of looking like a nice bright poppy seed cake it looks like a burned mud cake. The bright photo is from when I cut the soaps (end piece so design is ugly). The dark photo is after the evil has struck down my innocent, little bar.

Does anyone know what is causing this? Any way to prevent it?

I am using same soap recipe with other Essential oils and do not see the darkening of the bar....so not sure what is going on here unless lemongrass essential oil is oxidizing or something?

I have coconut, palm, palm kernel, olive oil, and castor oils in the recipe. I do use a bright yellow mica that adds to coloration. This is a goat milk soap bar by the way and I did not scorch the milk (stayed under 75F) when mixed with lye. Put in the freezer after it sets (but this does not seem to matter happens even if I do not). And I use sodium lactate too.

 

[Obsidian]

Lemongrass EO should not darken like that but since it's happening in the white area, its not the mica.
I'd suggest trying a different brand of EO, maybe what you have now isn't pure.
Alternatively, you could make a small unscented batch with the yellow mica and see how it behaves.

 

[stanekster]

Lemongrass EO should not darken like that but since it's happening in the white area, its not the mica.
I'd suggest trying a different brand of EO, maybe what you have now isn't pure.
Alternatively, you could make a small unscented batch with the yellow mica and see how it behaves.

I usually use Bulk Apothecary. Any recommendations on another EO vendor that someone uses they like (hopefully that used Lemongrass)?

 

[lsg]

I put my milk soap in the freezer right after pouring and leave it there for at least two days. Your soap could have started to gel before you put it in the freezer and finished the gel after you took it out.