Rasberry, green apple, vanilla and pepper in my glass of wine ?
First let’s make it clear ! When professional tasters identify the aromas contained in a wine, they call on their personal memory of flavors. When they claim they can detect that this wine has aromas of plums, leather, cigar box, fresh cut hay, gooseberries and butterscotch, this may seem completely esoteric and even unlikely for the novice … And yet …
These aromas can indeed end up in the glass when conducting a detailed olfactory analysis of a wine. But does that mean that the winemaker has added to its wine species of a particular fruit or other snake oil ? Or that he macerated strawberries, plums or green apples together with grapes? Not at all!
The flavors of the grape
The wine is the result of fermented grape juice. No other fruit in its composition. In fact, each variety has its own basic aromatic signature. For example, Gewurztraminer, a white grape of German origin will have aromas of lychee, rose and spices while the Syrah grape of the Rhone Valley will spread its flavours of black fruit and pepper. The aromatic characteristics of all varieties, however, have some slight differences depending on the region, climate or the soil in which they are grown. We’re talking about primary aromas (and thus natural) grapes.
The aromas of fermentation
Then, once the grapes have been crushed to extract the juice (or must if you prefer), so that the juice becomes wine, there will be fermentation. This is to say that sugar content in the grape must be transformed into alcohol. And to do that, there needs to be some yeast (natural or chemical). And that’s where these yeasts enter into the aromas game. Because besides the fact that they trigger the alcoholic fermentation and produce carbon dioxide, they also produce secondary aromatic components. Basically, this is where chemistry operates since the molecules of grapes, yeast and fermentation product will interact with each other and thus create this array of secondary aromas that we will perceive in our glass.
The aromas of aging
Finally, once fermentation is complete, either in a tank in an oak barrel or in the bottle, the wine will evolve over time and will generate tertiary aromas. Thus, during the maturation phase of the wine in barrels for example, there will be interaction between the young wine produced and aromatic components of the oak in which it is aged for a certain period of time. Hence the aromas of spices and vanilla if the wine is matured in barrels of French oak or coconut and more sweet notes if it’s aged in American oak barrels. Once bottled, the wine will continue to evolve, thanks to the minimal and very gradual oxygen’s influx in the bottle thanks the organic cork for example. In the case of bottled wines that already have several years of aging in the cellar, some tertiary aromas such as smoke, tobacco, or certain spices then take over on primary and secondary aromas.
What a bouquet !
This entire combination of primary, secondary and tertiary aromas generate the “bouquet” that everyone can try to identify thanks to its own sensory memory known aromas. One can also learn to recognize specifically certain types of aromas perhaps less usual, using tools such as « Le nez du vin” (the nose of the wine” , a box of chemically reproduced aromas. Otherwise, one of the best techniques is to continue to further explore the wine’s aromas like the professional taster by, let’s say, practicing whenever the opportunity arises. Cheers !