Understanding the Mellowing Effect of Bottle Aging on the Sensory Perceptions of Varietal Dry White Wines

The aging ability of dry white wines has been increasingly recognized. The present work aimed to identify which sensory features drive their quality assessment by experienced tasters. Individuals assessed several sensory attributes, using dark tasting glasses. Wines originated from the grape varieties Alvarinho, Arinto, Sauvignon Blanc and Pinot Bianco with a wide range of ages. Basic physical–chemical analysis, browning (Abs 420 nm), elemental composition and a partial volatile fraction were also determined. The overall quality scores were a function of complexity and balance and were negatively influenced by the perception of faultiness. The aging process could be associated with a continuous sensory space characterized by a declining perception of freshness and an intensification in the mellowed flavors. Despite their age, wines were characterized by an austere perception caused by their acidity, saltiness, bitterness, smoothness and dryness. Nevertheless, quality scores were similar from the youngest to the oldest tasted wines (17 years old). The exception was a Sauvignon Blanc wine from a recent vintage that was judged as faulty due to the perception of earthiness. Overall, the tasted wines displayed an unexpected aging ability as demonstrated by the difference between the predicted and real wine ages. To improve the recognition of old wines, the metaphor “mellowed by age” is proposed to describe flavors resulting from beneficial aging instead of “oxidized by age”.