Wednesday, October 6, 2010

Experiments in the workshop: Whipped shea without butter - stearic acid

For the second experiment, I'm using 10% stearic acid and 90% rice bran oil (I'm running out of shea oil and it's not cheap stuff!), hence the slightly yellowy cast of the picture to the left. Stearic acid is a great thickener, although it will make my creation feel more draggy than cetyl alcohol. And because it has a much higher melting point - about 69˚C compared to 49˚C for cetyl alcohol - I think it will withstand more of this annoying October heat we're getting in B.C.

I weighed the stearic and rice bran oil into a Pyrex jug, then set it into the double boiler. Again, it melted quickly. I put it in the freezer for about 20 minutes, then started whipping it with the whisk attachment. It went fluffy really quickly and looked like cake icing, all buttery and tasty (do not eat!).

It feels very nice on my skin, but it is definitely more occlusive than the version with cetyl alcohol (and I realize I'm using a different oil but it still feels heavier!) and there's very little play time to rub it in. Having said this, after about 20 minutes, it feels very moisturizing and smooth, but still a bit greasy. (I do like my products to be a little greasy!)

Out of all the versions I've made - you haven't seen them all yet! - this is definitely the greasiest and the most occlusive feeling.

Next time, I think I'll add a little cyclomethicone or ethylhexyl palmitate at 2% to 4% to give me a little more time to rub it in. If you like your products a little less greasy, try a drier oil like hazelnut, macadamia nut, or grapeseed oil or add an ester like C12-15 alkyl benzoate or cetearyl ethylhexanoate. (Click here for all the emollient links!)

Next separated out. I think both the cetyl alcohol and stearic acid versions need more of the thickener in them, so I'll try 20% of each next time, although I'm fairly sure using those amounts will feel a little too much on my skin.

I think I'll try cetearyl alcohol next! Join me tomorrow for a little information on this fatty alcohol, then come back on Friday to see my experiment!

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