Characterizing the impact of <i>Pediococcus</i> on wine sensory properties

The goal of this research was to determine the specific wine sensory impacts that the growth of Pediococcus can cause in wine. Initial screening of 19 different Pediococcus isolates was conducted in 2022 Oregon Pinot noir wine. Wines were assessed by experienced wine tasters using a modified napping method and ultra-flash profiling. No strong grouping of treatments based on aroma was observed, but there were two distinct groupings based on mouthfeel. Based on these results, four Pediococcus isolates were chosen and inoculated into 2023 Oregon Chardonnay, Merlot, and Pinot noir wines and grown for 9 weeks. Wines were assessed by rating all that applies sensory analysis using an experienced wine panel. A range of descriptors was used for wines inoculated with Pediococcus, many being typical aroma and mouthfeel descriptors for red or white wines. Some potentially negative terms, such as tortilla chip, musty, and cooked vegetable, were also used. P. inopinatus OW8 inoculation resulted in significantly different aromas in Chardonnay, Merlot, and Pinot noir wines, while P. parvulus WS9 inoculation did not alter wine aroma relative to the control wines. Additional aroma and mouthfeel differences were strain and wine specific with no consistent descriptor being used across Pediococcus isolates.