Matt Garcia,* James Osborne, and Elizabeth Tomasino
*Oregon State University, 421 NW 4th St, Apt B, Corvallis, OR, 97330 (matthew.garcia@oregonstate.edu)

This study investigated the influence of malolactic fermentation (MLF) timing on Pinot noir color and sensory properties. The addition of a non-Saccharomyces yeast, Torulaspora delbrueckii, during cold soak was also investigated due to potential interactions with the malolactic bacteria and production of acetaldehyde. Pinot noir wines were produced with and without cold soaking, with and without T. delbrueckii, and with a concurrent or sequential MLF. Cold soaking with T. delbrueckii yielded higher acetaldehyde concentrations at the end of cold soak and during alcoholic fermentation, but did not result in significant color differences at the end of MLF. Concurrent MLFs decreased color density and polymeric pigment content, but only if a cold soak had also been undertaken. After nine months of aging, differences in wine color and polymeric pigment content noted at the end of MLF were no longer present. Wines were assessed by a sensory panel to determine liking and sensory characteristics. Panelists were asked to rate their liking of each wine in clear and opaque glasses and to complete rate-all-that-apply descriptive analyses for aroma, taste, and mouthfeel. Wines produced without cold soaking had a significantly different aroma than those produced with a cold soak, while non-cold soak wines were significantly different from each other due to MLF timing. When not paired with cold soak, the concurrent MLF wine was described as having woody and spiced aromas, while the sequential MLF wine was described as having cedar, fruity, and herbal aromas. Use of T. delbrueckii during cold soaking resulted in wines described as having a more balanced and softer mouthfeel than their counterparts. Overall, MLF timing did not affect color once wines had been aged, but did result in wines with different aroma and mouthfeel properties. Cold soaking and use of T. delbrueckii also resulted in wine sensory changes.

Funding Support: Oregon Wine Board, American Vineyard Foundation