Smell is as powerful sense. A sniff of freshly baked bread can transport you back in time, remembering your grandma’s kitchen or a favourite bakery from your youth.


Smells are your brain reacting to combinations of molecules hitting receptors in your nose and interpreting those signals into something you recognize. Until recently scientists may have understood the structure of the smell molecule but it was nearly impossible to determine what smell you would be getting. A group of researchers set out to get it straight.

Scientists at Rockefeller University recruited 49 people and polled them on their perception of scents from 500 different chemicals. The subjects were asked to select a descriptor for each scent, choosing from a list of 19 “smell categories”: spices, bakery, sweet, fruit, grass, cold, decayed, wood, chemical, sour, acid, flower, musky, burnt, warm, fish, garlic, sweat and urine.

The researchers took all the collected data and started creating algorithms that could pair a molecule’s structural and chemical information with the “sent” it was most associated with. Through the IBM-run crowdsourced effort, the teams developed a system: in goes the molecule with its structural and chemical information, out comes the name of the scent. Though it is still early in this research the scientists expect they will eventually be able to mix smells with perfect accuracy.

It’s conceivable that an odour wheel could be created, much like a colour wheel, only for smell. So, one day we may actually be capable of mixing smells like we mix paint, based on the structure of molecules rather than subjective opinions. Who doesn’t want a future where you sit down in chemistry class, look at a molecule and shout, “Hey, professor, that molecule smells like piss!”