Differentiating sensations from perceptions in the practice of olfaction

From the chapter: Think like a somm

Alexandre Schmitt, the French master of olfaction.

When I was a 21-year-old sommelier I honed my craft like many others—through constant blind or double-blind tastings. Something I rarely do these days except in the occasional wine judgings spread out over the course of each year.

Youth will be served, but sometimes it takes an “older guy” to show you the ropes. I have good memories of one senior wine professional named Dave, with whom I often enjoyed verbal jousts when I was an up and coming 20-something. Dave was an aroma savant. Very irritating, but useful. I would say, “This Zinfandel has a real fresh berry quality.” He’d look at me with a pained expression and ask, “What do you mean? There are all kinds of berries—there are blackberries, raspberries, strawberries, blueberries, currants, elderberries, gooseberries, and on and on, and none of them really smell the same.” Of course I’d be stumped, because as a 20-something who grew up in Hawaii, I had zero experience with half the berries he was talking about.

Then I’d say something like, “This Napa Valley Cabernet is very minty—you can’t dispute that, Dave.” He’d say, “You still don’t know what you’re talking about. There’s a big difference between the smell of spearmint and peppermint, not to mention chocolate mint, or the artificial ‘double-mint’ you find in a Wrigley’s. Or are you talking about eucalyptus? That’s a common mistake many so-called wine experts often make, because eucalyptus does not resemble leafy mints, plus there are all kinds of eucalyptus, most of them smelling more like cat pee than any kind of minty mint.”

Dave retired long before I became an older "wine guy" myself, but truth be told, I’m still grasping at aromatic straws. This hit home in 2015, and then later in 2019, when I sat through two multi-day workshops put on by a Frenchman named Alexandre Schmitt. In recent years Schmitt has been spending a lot of time in California conducting what he calls Olfactory Seminars: Aimed at introducing wine professionals—especially winemakers—to a more disciplined way of identifying smells, particularly from the perspective of a professional perfumer, which is Schmitt’s original profession.

The author (far left) with oldest daughter on his chair, in another time (1981) and place (his backyard in Hawaii), blind tasting with one of his professional groups.

Schmitt, who is from Bordeaux, began his career as a creator of perfumes in Paris and London, and taught perfumery and aroma formulation at Bordeaux Pharmacy. It was there, in the early 2000s, that he met Christian Moueix of Château Pétrus, and over the course of 12 years he and Moueix met monthly over lunch to share their knowledge of aromas and wines. “Today,” says Schmitt, “I am totally dedicated to the wine field, doing aromatic seminars and wine consulting.”

In his introduction to Olfaction Seminars, Schmitt writes: “The best musicians spend years studying music theory and practicing scales on a daily basis. Why should it be different for wine professionals who use their sense of smell every day?” Two of Schmitt's watchwords are “precision” and “freedom.” That is to say: Learning the rules of objective wine description—avoiding both incorrect identifications and dubious flights of fancy—and through that process, coaching ourselves to develop our own, reliable “classification of aromas.”

In the classroom, Schmitt is by necessity a harsh instructor; but like a bemused guide leading you through the dark, he marks the way by presenting small strips of paper soaked in a scent, which he then asks you to describe and, if possible, identify. In an early round he presented two unidentified strips, both coming across as citruses: One smelling strong, acidic, almost bitter and animal-like, which turned out to be lemon; and the other smelling sweeter and less acidic, with a slight soapy greenness, which we learned was lime. Intellectually, we all know what lemons and limes are, but distinguishing the two purely on the basis of smell is another matter. The fumbling attempt at identifying presumably everyday smells can be a humbling experience. When you fail you realize just how much your brain is disconnected from your senses.

Right away, a professional trained in traditional wine tasting methodology—particularly those influenced by U.C. Davis systems first devised by Professors Amerine and Roessler over 50 years ago—will say that you cannot “smell” senses of acidity, sweetness and bitterness, they must be tasted on the tongue. Schmitt says that this is a fallacy because, in reality, “we cannot separate the sense of smell from sense of taste.” The accumulation of all sensations in our memory bank—that is, our syncretic perception—is how we develop our olfactory system from the moment we become conscious beings.

For example: Not being able to smell a lime without also thinking of one sweaty, delirious night in a gritty Mexican border town, the sound of música norteña in your ear, feeling the pain of a tattoo needle, and waking up with sour, salty residues in your mouth and the sweet, solvent smell of tequila on your clothes. Schmitt actually uses this analogy in the class—revealing, I think, the wild side of his personal life—although it's hard to imagine that someone who used to lunch monthly with Christian Mouiex would ever hang himself out to dry like that.

Schmitt starts off his workshops by talking about our two basic functions, sensation and perception. “Sensation is perceived by about 100 million receptors located in the nostrils, which relay aromas directly from the nerve to the brain. Perception involves the brain, which wants to scan and analyze sensations, and describe what we are smelling.” What is important to Schmitt is that wine professionals learn to differentiate sensations from perception. Sensations can be exact, but it is in the perception, or interpretation, where most tasters lack precision, often finding themselves lost. Schmitt demonstrates the degree of difficulty by presenting strips soaked in liquefied essences of lemon verbena (a green, astringent citrus smell), lemon grass (leafy citrus, like herbal tea), grapefruit (another soapy, bittersweet citrus), and orange (citrus with white flowers). While I sat in roomfuls of seasoned wine professionals, almost none of them could readily delineate each and every one of the scents without our usual visual cues.

The challenge was literally in our heads. On each day, by the time I reached the thirtieth or so aroma compound proffered by Schmitt I found myself confronting familiar aromas with no precise words to apply. At times, the increasing volume felt like I was being asked to recite the Quran… backwards. Call it brain or mental fatigue. What it was not was an actual tiring of the senses. My nose continued to work just fine. I could, for instance, recognize but not quite verbalize cumin, a clearly musky, sweaty, savory scent which I know all too well as a common kitchen herb used in curry and chili, which I love and use all the time. Even though I associate cumin with curry, says Schmitt, “It is incorrect to call this a ‘curry’ aroma [curries vary hugely and often consist of well over a dozen different spices]... it should be memorized as ‘cumin,’ especially because it is an aroma often found in well aged wines that are not oxidized.”

(Dangerously) good times… mezcal bar in Oaxaca.

The smell of black pepper, according to Schmitt, “is not always identified because individuals have varying degrees of sensitivity to it.” Therefore, some professionals jump on the smell right away, while others remain oblivious. Schmitt describes black pepper as a spice smell that gives off a “hot” feeling to the nose derived from the presence of rotundone (a sesquiterpene), which sometimes also suggests pine or cedar. He adds, “You might unconsciously smell pepper in a wine, and only notice it through the process of ‘anamorphism’”—that is, something that you recognize once it is suggested to you.

Examples of aromas presented by Schmitt on his white strips, along with his comments:

• Clove⏤“A ‘dry’ smell that suggests pepper and smokiness, typical of wines aged in toasted barrels, and commonly mistaken for cinnamon because of the association, not because it is the same."

• Pine⏤“A ’fresh’ smell, not as ‘dry’ as cedarwood, suggesting cooling sensations, resin, even citrus.”

• Cinnamon⏤“Sweeter and earthy, and contrary to popular opinion rarely found in wines.”

• Spearmint⏤“A ‘sweet’ smell suggesting leafy, fragrant green herbs.”

• Fennel⏤“A floral/green anise-like aroma because it is part of the anise family of scents, although not as strongly ‘anise’ as what you find in pastis.”

• Black licorice⏤"A confectionary’s scent not of the natural world, but rather manufactured by combining anise with caramel and a woodsy molecule."

• Oak lactone⏤“Anise/dill/celery-like aroma common to toasted oak.”

• Maltol⏤"Burnt caramel-like vanillin molecule, common in oak barrels."

• Furanéol⏤"Coconut butter-like vanillin, also common in oak aged wines."

While it is possible to learn how to identify each scent with some precision, Schmitt makes the point of reminding us that the images that pop up in the mind stored up from a lifetime of taste/smell experiences are often more than just odor-related. They are also “visual, acoustic, olfactory, gustatory, tactile, and thermal.”

In other words, unless you are able to “feel” or even see, hear, taste or emotionally relate to smells, you are less likely to be able to delineate them. The trick is to embrace what Schmitt calls “syncretic perception”—comparable to the proverbial “Proustian moment” triggered by the scent of a single madeleine—which can lead to a more organized memorization of odors useful in all facets of wine-related industries.

One interesting example of the Proustrian analogy was a scent presented as a variation of citrus. Only one person in a room of about 20 wine professionals could identify this scent as bergamot—which has a citrus note faintly suggesting soapiness combined with both peppery spice and dusty drawer smells—but only because that person happened to be someone who regularly drinks Earl Grey tea, which is spiced with bergamot. That same person also added that he has always associated the smell of bergamot with the Touriga Nacional grape—one great example of using a personal syncretic experience to sharpen the ability to discern grape content of wines!

“It is not surprising,” says Schmitt, “that different tasters can experience very similar feelings but express different judgements.” But by educating ourselves through olfaction, we can develop a “confidence that is essential in the understanding of wine’s aromatic complexity.”

Wine tasting, says Schmitt, is indeed a "subjective activity," but it can also be “erroneous.” But once you develop a more precise, practiced and expanded knowledge of aromas and flavors, "your ability to distinguish and describe the wines of the world is sure to expand."