Over on my main blog, Strings 'n Things, I wrote about a Vitamin C serum that I'm experimenting with. (I had planned on posting that post here but Blogger wasn't cooperating.) It's made with all sorts of wonderful ingredients, including some that are meant to help keep the Vitamin C (L-ascorbic acid) from oxidizing. It also includes an ingredient called Sea Kelp Bioferment, which is, basically, lacto-fermented seaweed, which is why the working name for this serum is Vitamin Sea Serum. (Clever huh?)
Vitamin C, or L-ascorbic acid, is quite stable when it's in a solid (powder) form but when it's in a solution, it oxidizes rather quickly. If you make a very simple Vitamin C serum, you'd have to remake it every 7-10 days. Eventually, the solution will discolour to orange and then brown. That's how you'll know that it has oxidized. It can also discolour your hair if you manage to get it in your hair. As I did. I couldn't figure out at first why the hair around my face was turning orange. Yup, oxidizing Vitamin C serum.
To that end, I eventually came across the recipe I now use. And, because I know that L-ascorbic acid eventually oxidizes, I decided to put this serum to the test.
It isn't the easiest to see in this picture but in that pipette is a bit of the Vitamin Sea Serum. I've put in on my kitchen window sill, where it gets full sun in the mornings. I'm going to leave it there until it starts to change colour. I want to know how long that takes. So far, it's been 24 hours with no visible change.
I'll keep you updated.