Does wine really smell like blueberries?
Is there a scientific basis for the flamboyant aroma descriptions which can often be found on labels or in menus? Is it down to individual perception?
Yes, and yes. To a certain extent, a wine’s “bouquet” will be different for every person that smells it, because the smelling apparatus of each individual will be slightly different, and because the smells the individual has been exposed to throughout his or her life may be different, or have different names. Even the environment in which the individual is smelling a wine may have an effect on its perceived aroma. However, chemically speaking, there are indeed molecular compounds which are associated with the smell of certain well known foodstuffs or other substances – whether because they are naturally present in that substance or foodstuff, or because they have been used to mimic the aroma artificially – and some of these molecular compounds can be found in wine. Their presence and concentration will depend on a number of factors, including the grape variety and various choices made by the winemaker (e.g. oak maturation, anaerobic winemaking, cold fermentation, etc.).
Some smells are almost unmistakable and are predominantly attributable to a single molecular compound which is naturally present in the foodstuff with which the smell is associated. For instance, the smell of vanilla derives predominantly from a phenolic aldehyde called vanillin, which occurs naturally in cured vanilla pods. Some smells are more complex, and attributable to several different molecular compounds which are all naturally present in the foodstuff with which the smell is associated. For instance, there are more than six different aroma compounds that can be associated with the smell of pineapple, all of which are naturally present in pineapples. Some “unmistakable” smells are attributable to a molecular compound which is regularly used as an artificial flavouring, to mimic the smell of a particular foodstuff. For instance, the smell of banana is regularly mimicked using a simple ester called isoamyl acetate, which is naturally present in bananas but only partially responsible for their smell. So strong is the association of isoamyl acetate with the smell of bananas that it has come to be called the “banana ester” by chemists.
It should of course be emphasised that just because a wine is redolent of strawberries does NOT mean that strawberries were blended into the wine.
In sum, there is indeed a scientific basis for the description of a wine’s bouquet in terms of the smell of existing foods or substances, and to the trained taster, a description using this vocabulary can indicate something about the grape variety/ies, the winemaking techniques, and even the geographical origin of the wine. This description is not necessarily “correct” and may differ wildly from an individual’s perception of the same wine, but it is valid and can be very useful. As with any language, it is a case of being able to interpret the terms used and mapping what one smells in the glass with the language that is usually employed to describe it. This “aromatic language” will undoubtedly have a strong cultural dependence. Perhaps more interesting in terms of interpreting what is in the glass is determining whether the perceived aroma is a simple or complex one… and whether it is pleasant!
For some fantastic infographics of the smells associated with different molecular compounds see “Table of Esters and their Smells” and “Table of Organic Compounds and their Smells.” Many of these compounds can also be found in wine. “Ingredients of an All-Natural Banana/Strawberry/Pineapple/Lemon” show how many of these compounds are also naturally present in various fruits.