Thursday, December 16, 2010
Everything you ever wanted to know about perfume but were afraid to ask.... Chemistry Class Remix
Actually those of you hoping for a good old fashioned perfume review or a write up on the history of some obscure French perfume house, or my latest vintage perfume fixation- I hope the beautiful image of a model wearing Dior in Paris, 1950 is welcome respite. I promise to return very soon with more, more, more... soon.
And if you're a chemistry hater, well then read no further; you won't like it what's in store below.
But those of you who are fascinated with the prospects of rehabilitating perfumes in our collections that seem to be going or have gone, BAD: just know, I'm still researching. In the meantime, I've been chasing down the whole chemistry thing that happens when perfumes decide to go over to the dark side.
Remember those terpenes I mentioned last time? Well , it turns out they're in virtually every floral essence you can think of. I guess that's why almost any perfume can potentially "spoil". If I'd been properly trained as a perfumist/flavorist instead of merely playing Nancy Drew with a bottle of Guerlain, maybe I'd have known about the oxidation of terpenes sooner.
Turns out "extended or careless storage" allows oxidation to occur, which in turn can create "aroma flaws". Thus an orange note may take on a turpentine-like scent after D-limonene has oxidized into carvone. Even though the various terpenes only differ by small variations in their spatial structures, the human nose is sensitive enough to differentiate between them all.
We know (limited) exposures to open air can sometimes fix the problem- but whether it's because you blow off the oxidation products that have accumulated, or mix them back into the perfume solution, where they dilute or convert back to their original form via a conversion reaction (or something like that), I have no idea. No one really cares either, other than the accidental perfume preservationist. And we really only need to know what works; for that, we only have the accumulated knowledge we share with each other to go on. But yeah, based on the anecdotes and the little experiments I've been conducting, it works. It worked so well in fact that I've had to delay my charcoal experiment until I can locate another suitably frazzled perfume, since the ad-hock air cure completely rehabilitated my bottle of Mitsouko (...and a couple of other forerunners. Really.) Since it's not likely to hurt anything either, why not try it next time?
The Vintage Perfume Vault, where the scent of yesterday's vogue lives.
Oxford (on the web)
Fragrances, vitamins and hormones - the ABC of terpenes. Published in Beauty Forum
2010 (3), 56-58.