Chemistry you can wear

The science behind your signature scent.

BEFORE HE BECAME A New York City taxi driver and long before he became an internationally lauded perfumer, Christopher Brosius visited his grandfather’s sawmill in Greenbriar, Pennsylvania, almost weekly, playing in the yard because he was forbidden to enter his grandfather’s workshop, full of lathes, grinders and welding machines. What he remembers most is how the workshop smelled: hay, sawdust thick axle grease, tobacco, damp concrete, and hands washed with Lava soap. When Brosius started his own scent company, called CB I Hate Perfume, he decided to turn what he remembered of the sawmill into something he could wear. The result was a fragrance he calls Greenbriar 1968.

Successfully creating a scent like Greenbriar 1968 is a lot like assembling a puzzle that happens to be invisible. The instructions: choose and blend chemicals so that the resulting compound smells both accurate and pleasant. Don’t burn or alter the odours of the fragile (and in some cases flammable) ingredients while doing this. And don’t get a headache.

“You can’t just distill motor oil,” says Josh Meyer, a selftaught perfumer who started the cologne company Imaginary Authors in Oregon in 2012. “There’s no such thing as a leather essential oil. You’re just taking aroma chemicals and mixing them to make it smell like that.”

To inform their blending, scent-makers can use a specialised technology called headspace analysis. “There is a glass reservoir that you can put around a flower or whatever you want. You can put your foot in it or your cat or anything,” says Christophe Laudamiel, a perfumer who created, among other famous scents, that ubiquitous Abercrombie & Fitch cologne. The machine then uses heat and suction to capture the odour of flower, foot or cat on a sponge. A gas chromatograph heats the sponge until the chemicals on it evaporate and separate, and then a mass spectrometer resolves these into individual molecules.

Because natural objects can contain thousands of scent-producing chemicals, at best headspace technology provides a very close approximation. This is where the art comes in. The more difficult a scent is to literally recreate, the more important it is for a perfumer to be able to fake it. The chemicals that make beer smell good evaporate too quickly to work well in a perfume. The same is true of petrol. (Plus it’s toxic.) Apricots are tough to mimic and there aren’t enough starchy-smelling chemicals available to make a good steamed rice. Approximations of these scents exist, but they can sometimes smell uncomfortably distant from the real thing, like an uncanny valley for your nose. Brosius, who once won an award for a perfume that smells like snow, likens the process to that of an impressionist painting a tree. When done well, you can still see what the painter is getting at. And you can smell it too.