Exposure to oxygen during white wine production is generally considered to negatively impact color, aroma, flavor, and shelf life. However, hyperoxidation, the intentional exposure of recently pressed juice to high levels of oxygen, has been used to initiate enzymatically-controlled oxidation cascades that remove the phenolic precursors of oxidizable compounds. Removal of these precursors prior to vinification may lead to a product with improved color over time, greater shelf stability, and less harsh or bitter flavors. Optimized storage temperatures can also increase the shelf life of white wines by maintaining terpene and ester contents and by preventing the formation of new detrimental flavor constituents. The overall effects of hyperoxidation and storage conditions on white wine quality is still in dispute and has created a need to critically evaluate the combined effects of hyperoxidation and storage temperatures on Riesling wines. This study examines control and hyperoxidated wines at three storage temperatures (63, 75, and 90°F) through chemical and sensory evaluations over time. Initially, a trained sensory panel detected no significant differences in aroma or flavor characteristics between hyperoxidated and control wines before entering storage treatments. After one year of storage, wines held at 63°F retained significantly higher sensory ratings for overall aroma intensity, fruit aroma, and fruit flavor than wines stored at the higher temperatures. Wines stored at 90°F developed darker colors, oxidized aroma characteristics, and a loss of varietal flavor attributes. These detrimental characteristics were first detected in the control wines before they were observed in the hyperoxidated wines. The sensory results of this study were compared with SPME-GC-MS analyses of the aromatic volatile compounds. The successful determination of optimized hyperoxidation treatments could potentially benefit both wineries and consumers with longer-lasting white wines even under challenging storage conditions.

Funding Support: Ohio Grape Industries Committee and The Ohio State University