One of the cultural myths of smell that I blew up in What the Nose Knows concerns those jars of coffee beans you often see on the fragrance counter in the department store. The idea is that sniffing coffee beans acts as an olfactory palate cleanser, or a “reset button for the nose.”
There is a basis in psychophysiology for expecting difficulties when sampling one perfume after another. A person might adapt or become temporarily less sensitive to certain notes. His nasal passages might become flooded with a cacophony of scent, making it difficult to tell one sample from another. On the other hand, there is no scientific explanation—none, zip, nada—why the hundreds of different volatile compounds in coffee aroma would help with either of these scenarios.
In fact, the very concept of a palate cleanser is suspect. The one good study on the topic found that none of the usual palate cleansing methods (eating bread, rinsing with water, etc.) made any difference whatsoever in flavor perception.
Now comes a study in Perceptual and Motor Skills by psychologist Alexis Grosofsky and her colleagues at Beloit College in Wisconsin. They tackle the Bean Meme head-on, in a sniff test with college students and four commercial perfumes. (Somewhat hilariously, the scents are from the Designer Imposter collection of Parfums de Coeur. You know the ones: “If you like Calvin Klein’s Obsession, you’ll love our Confess.” Hey, Calvin Klein doesn’t fit into every research budget. And in any case, it makes absolutely no difference to the experiment.)
Each participant smelled three of the four perfumes from a dry down blotter in a jar, and rated them for pleasantness, intensity, and masculinity/femininity. Next came the palate cleanser: the subject sniffed a container full of coffee beans, lemon slices, or just plain air. Then the subject was given all four perfume samples—the original three plus a new one—and asked to pick out the new fragrance.
College students do pretty well on this test: they correctly fingered the new perfume 57% of the time after sniffing plain air, 62% of the time after sniffing beans, and 86% of the time after lemon. The differences between “palate cleansing” treatments were not statistically significant.
Smelling coffee beans did not results in higher mean accuracy of identification of novel fragrances. . . . Coffee beans and lemon seem to have no special refreshing properties. Fragrance sellers may wish to reconsider the practice of providing coffee beans to their customers.Amen to that.