Atypical Aging in Wine: History, Description and Analysis
Atypical aging (ATA) is a flavor defect in white wines, particularly but not limited to aromatic whites, where wine loses its varietal flavors very rapidly and atypical, waxy, furniture varnish, and dish rag like aromas appear when the wine is only 6 months to just over a year old. ATA is different from normal wine aging in both rate and flavor characteristics. This thesis is comprised of three papers: the first being a discussion of the history of research on the topic; next, a report on the process of describing ATA as a sensory phenomenon (taste panel results); the third paper describes research done to find ATA?s causes and responsible compounds. Work done in Germany regarding ATA has focused primarily on ortho-aminoacetophenone (O-AP), a compound responsible for the ?foxy? note in American labrusca grapes. O-AP does not seem to be an important compound in New York wines with ATA, however. What is agreed upon is the oxidative nature of ATA and the need for antioxidants beyond SO2, such as ascorbic acid, to protect at-risk wines. During the 2001-2003 growing seasons, trials were conducted in a Riesling vineyard in the Finger Lakes region of New York State to study the effects of irrigation and nitrogen fertilization on ATA development. Wines made from this fruit were then analyzed sensorially and chemically to determine any differences these treatments may have had on wine quality, particularly in relation to the atypical aging defect. We found that wines made from irrigated fruit tended to have both more varietal flavor character and less of the waxy, ?dishrag? off-flavor than the wines made from the non-irrigated fruit. Nitrogen additions, or lack thereof, seemed to play a much smaller role in the sensory quality of the wines. Although attempts to chemically quantify this phenomenon have been inconclusive, results point toward effective management of water and nutrients in the vineyard being important steps in helping wines avoid ATA.
dissertation or thesis