Have you ever wondered whether a wine that smells of sun-ripened peaches came from a vineyard next to an orchard? Or whether the chalky note in an Old World wine sprang right from the soil into your glass? Where do the scents found in wine come from?
Given how little we know about the mechanics of taste and smell, it’s understandable.
Science has taught us some things, however. First, the smells apparent in wine do not come from the surrounding environment. There are only two exceptions: smoke from wildfires and the scent of eucalyptus from surrounding trees. But, neither of these wines will likely make it to market.
Here’s what else we know: The aroma and tastes of wine result from compounds within the grape itself, the fermentation process, and any aging regimen. At each stage of winemaking, molecules separate and recombine to form an entirely new creation. And this creation is alive, changing, and evolving until the moment it is released.
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Wine Tasting and Anosmia
For people who love wine, anosmia can be a life-altering condition. The loss of the sense of smell destroys the ability to taste wine. For a sommelier, this can be the end of their career.
However, focusing on wine tasting and training to become a sommelier can be part of your therapeutic recovery. Focusing on scents in professional sommelier programs is a great way to recover, learn a new skill, and possibly start a new career.
Sommelier Jargon and Scent
We call scents in wine derived from the grape “Primary aromas.” These range from fruity to floral and herbaceous to funky. A sommelier can identify a grape variety in a blind tasting based on these aromas, also known as “varietal fingerprints.”
Secondary aromas are those that arise from fermentation. The yeast used during fermentation can play a significant role in imparting flavor to wine, and specific winemaking techniques can bring about biscuity or nutty aromas.
Finally, tertiary aromas come about during the aging process. The most common are baking spice notes that come from oak aging, but even aging in the bottle will play a role in how the wine tastes.
The Many Scents Found in Wine
The typical taster can identify four to five aromas in a given wine. Fruit aromas are the easiest to discern. These include citrus, tropical, orchard fruit scents in white wine and berry scents in red wine. You do not need a wine aroma chart to find these scents! Even if a wine smells bad to you, record the scents you recognize.
But a well-made wine will smell like more than just fruit: it should also have earthy notes. Earth may include the smell of soil, clay, herbs, flowers, and even sea salt. Depending on your background, you may find those earthy notes compelling or completely off-putting, at least at first. (If you struggle to appreciate earth aromas, try pairing them with food. Often the earth notes will marry beautifully with an adequately seasoned dish.) You may need a wine aroma kit to dive fully into these aromas.
Earthy notes will become more prominent as wine ages. Fresh fruit will transform into dried or stewed fruits, like prunes or figs. In red wines, tobacco and mushroom will develop, too. White wines start to give off scents of dried apricot or orange marmalade. Other tertiary characteristics include nutty and spicy aromas. Wine professionals refer to these traits of aged wines as the “bouquet.”
Taking the time to enjoy the panoply of scents in wine is the mark of a true wine expert. Moreover, doing so pays proper tribute to the winemaker and the land.
The Science Behind the Scents Found in Wine
PYRAZINES
This group of compounds can originate in the grapes themselves. They are not subject to microbial action during fermentation or aging.
ESTERS
Esters are naturally present in grapes as they ripen, but are more likely to be formed from microbial action during fermentation. They react with acids and alcohol during the aging process. They are essential to the scents found in wine.Fruit aromas associated with esters include the strawberry and raspberry of classic Pinot Noir, Grenache, and Syrah; blackcurrant, or cassis, which is a main aromatic in Cabernet and Syrah.
Vegetal aromas like the bell peppers in a Cabernet Franc and the hints of asparagus sometimes found in Merlot are produced by isobutyl. Other esters include rose oil (phenethyl acetate), lavender, and some Muscat derivatives (linalyl acetate), acetone, i.e., nail polish remover (ethyl acetate), and soap (ethyl laurate).
ALDEHYDES
These are formed by microbial activity and by oxidation during the aging process. We sense Aldehydes as tart, under-ripe red cherries in Pinot Noir and darker cherries in Sangiovese, Cabernet, and Syrah. In older, more oxidized wine, aldehydes impart a nutty characteristic.
MORE
Of course, there are many more scents found in wine and its corollary aromatic molecules. Some of the more important of these are the mercaptans which are derivatives of sulfurs formed by yeast during fermentation. When found in small amounts, they can evoke passion fruit and tropical melons; when disproportionately high, they can be unpleasant, such as the pungent cat pee smell of some Sauvignon Blancs. Ethyl mercaptan can be perceived as earthy or have the scent of a freshly struck match (think sulfur) and the burnt rubber some find in Syrah. Dimethyl mercaptan has varied tones: stewed vegetables, truffles, or mushrooms can be detected.
Vanillin is found in oak, as are the lactones that come off as coconut. Aldehydes impart toasty flavors in new oak. Clove, cinnamon, butterscotch, and caramel can all be attributed to the interaction of compounds in wine and the composition of the barrels during aging.
