Originally published by Penn State Extension www.extension.psu.edu/enology

Summary of Wine Aroma Compounds and Descriptors
Wine aroma is a term used to describe what we smell through our nasal passageway in the nose. Wine flavor, in comparison, is made up of those aromas that are sensed through the nasal passageway in the mouth (retronasal sensation). Wine aroma and flavor can come from four different parts of the winemaking process:

1) The variety (grapes)
2) The fermentation (yeast/bacterial conversion of aroma compounds)
3) The aging process
4) Wine defects

Each stage in the winemaking process can alter the wine’s aroma. A single decision (i.e. whole cluster pressing vs. crushing/destemming followed by pressing) has the potential to change the aroma composition, as well as the wine’s chemistry. This point is emphasized in the following flow chart:
To date, there are approximately 850 aroma compounds identified in wine. Some of these compounds are present in all wines, but at varying concentrations. These are classified as “non-specific aromas.” However, other compounds are classified as “specific aromas” because they contribute to the varietal aroma/flavor of that variety and/or are specifically found in only that variety. An example of this includes certain methoxypryazines (bell pepper aroma) found regularly in Cabernet Sauvignon, Cabernet Franc, and Sauvignon Blanc or methyl anthranilate (grape aroma) found in Concord ..