I had a really interesting week at work this week. On Monday I made my first sunscreen. From scratch! I was so excited when it actually turned out OK. It will actually be a moisturiser with SPF 15 when I'm finished but to start with I made a sunscreen. Sunscreens are really hard to make and especially "natural" ones.
First you have the Zinc which likes a neutral pH, versus the preservative which likes a low pH. Then you have the zinc + oil + water which don't go together that well. Sunscreens are quite hard to stabilize too, they have a tendency to separate down the track.
Mondays V1 turned out a nice thick white cream but created a ghosting effect which turns the skin slightly white. Tuesdays V2 turned out thicker and matte with even more of a ghosting effect. Wednesdays V3 is a glossy cream and creates a slight ghosting effect which fades after an hour. V3 is definitely the nicest version so far but I'm not sure its going to stay together. Only time will tell. I'll be testing V3 on Friday when we go to the zoo. Half my face will have cream on and half without. We don't test on animals but we test on me! I should really get risk money!
At present the only way to test the SPF of a sunscreen is to send it to a lab where they test it by actually applying it to someone's (most likely a student) back and then sit them in the sun for a specific amount of time, then measure the square of sun screened skin against un-sun screened skin. Primitive and expensive!
I also have been developing a shower oil for winter. I didn't really know what a shower oil was either but while playing round with different ingredients I managed to create this really cool gooey gel which is really moisturising. It rubs on clear and glossy like a thick oil, then when you wash it off it turns milky and leave the skin feeling really smooth and moisturised It was a complete accident and the secret of the consistency is in the method of manufacture. Monday I made 3 versions. On Tuesday I did 4 batches and every single one failed. Tuesday was one of those days when R&D is just plain depressing! Anyway Wednesday I managed to reproduce it so now that I know exactly how to make it I just have to tweak it and make sure that its stable.