Wine is produced from fermentation, usually fruit, primarily grapes (almost anything organic with sugar can be fermented to produce an alcoholic beverage – grain, vegetables, even milk). The fruits are harvested, crushed, fermented, and then aged. The fermentation process produces the alcohol content, while the aging process contributes greatly to the flavors. The juice is made up of chemical compounds, including sugars, volatile organics, and alcohols. It is the interaction of these molecules that produces the aroma and flavor of the wine. Wine can contain hundreds of different molecules that alone or in combination, can produce an incredible variety of aromas.
The nose is an incredible organ (reference my previous blog, Food Pairing 101); it can distinguish thousands of different aromas, even those at a very low concentration. Throughout our lifetimes, we recognize and catalog aromas (good and bad), and relate them to life events, various foods, people, places, and things. These aromas are made up of molecules, known as volatile organic compounds, which create the scents that surround us.
Wine has been found to contain the same molecules that give scent to other plants and materials, and – when sniffed by a fearless wine taster – delivers those same aromas to us. Some wines have very distinct characteristics. The signature aroma of Syrah, for example, is pepper. The flavor of vanilla in wines that are aged in oak comes from vanillin, the same compound that gives vanilla its aroma, and the aroma of butter found in Chardonnay comes from the naturally occurring chemical diacetyl. Strangely enough, the only aroma that you do not get from wine is that of grape (other than wine made from muscat).
The reason that we are interested in the aroma of wine is that they give us a common language to describe the wine, and to quantify the reasons we like, or dislike, a particular wine. There’s been a lot written about the “myth” of being able to distinguish more than a few aromas or flavors from a particular wine; one proof offered is that different tasters will detect different aromas from the same wine, and the same taster will detect different characteristics from one wine tasted on different days. It is pretty easy to make a case against all of those arguments:
Different people have different sensitivity to the same aromas – in fact, it is possible to be “scent blind” to particular aromas, and hypersensitive to others.
Even though a bottling of wine might put the same wine in a variety of bottles, there’s no guarantee that the amount of oxygen is the same, or that the exposure to oxygen during the bottling process doesn’t affect the wine.
Trying wine from the same bottle on different days will certainly see differences, as the oxygen introduced from opening and pouring will have an effect on the wine.
Ultimately, wine is meant to be experienced by all the senses; so pour a glass, inhale those luxurious aromas, and enjoy!