Bloodhounds and sharks are known to be champions of smell. Human beings? Not so much. But a new study suggests the human nose is more skilled than previously thought, capable of detecting roughly 1 trillion different odors.
What does that mean for wine lovers? Since experts believe up to 90 percent of the complexity we taste in wine is actually aromas picked up by our nose while drinking, it means you have a more powerful tool on the front of your face than you might realize.
Prior to this study, the number of individual scents that the human nose was allegedly able to isolate was set at 10,000. The number dates back to 1927, when two American chemists sought a way to classify odors. According to their math, there were 6,561 different smells the human olfactory system could identify. This number was later rounded up to 10,000 (no one really knows why).
Dr. Leslie Vosshall, who studies olfaction at New York's Rockefeller University and is an investigator with the Howard Hughes Medical Institute (HHMI), was skeptical of that number. “Objectively, everybody should have known that that 10,000 number had to be wrong,” she told Wine Spectator.
Vosshall and her research group decided to test the capacity of the human olfactory system in much the same manner visual or aural capacities are tested. “We know exactly the range of sound frequencies that people can hear, not because someone made it up, but because it was tested,” said Vosshall. "We didn't just make up the fact that humans can't see infrared or ultraviolet light. Somebody took the time to test it.”
For their test, they employed 128 different odorant molecules combined into random mixtures of 10, 20 or 30, which made them largely unfamiliar. “We didn't want them to be explicitly recognizable, so most of our mixtures were pretty nasty and weird,” Vosshall said. “We wanted people to pay attention to 'here's this really complex thing—can I pick another complex thing as being different?'” The volunteers were presented with three vials of scents at a time–two matched, and one different and were then asked to identify the one that was different. Each of the 26 volunteers made 264 such comparisons.
So how does that add up to 1 trillion? Vosshall's team tallied how often the volunteers were able to correctly identify the different vial. Then they extrapolated how many unique scents the average person would be able to distinguish if presented with all possible mixtures that could be made from the 128 odorants. “It's like the way the census works: to count the number of people who live in the United States, you don't knock on every single door,” said Vosshall. "You sample and then extrapolate."
Charles Curtis, a wine-collecting consultant and the former head of Christie’s Asia and Americas wine division, was intrigued by this discovery. But he cautioned that even though our noses are better than we thought, when it comes to detecting odors in wine, practice makes perfect. “The challenge for wine lovers is to smell mindfully—to really think when you're analyzing a wine," said Curtis. "Combining our sense of smell with our ability to analyze and reason is the part of this discovery that is really interesting."