Emily Stoffel, Samantha Anderson, Cate Krystoff, and L. Federico Casassa*
*California Polytechnic State University, 1 Grand Avenue, San Luis Obispo, CA, 93407 (lcasassa@calpoly.edu)

Wine sensory perception has a strong temporal component, especially with regard to the perception of retro-nasal flavor and astringency after expectoration. The purpose of this experiment was to evaluate the temporal impact post-expectoration on Merlot, Malbec, and Petite Sirah wines that had been co-fermented, in contrast to wines that were blended post-alcoholic fermentation and post-malolactic fermentation along with single-cultivar controls. Each of the three winemaking techniques used a combination of each cultivar: Merlot-Malbec, Merlot-Petite Sirah, Malbec-Petite Sirah, and Merlot-Malbec-Petite Sirah. Selected phenolic classes and color were followed up to 14 months postbottling. The 15 treatments were also evaluated four times using Temporal Dominance of Sensations by 11 trained panelists for five retro-nasal aroma attributes (fruit, floral, mineral, vegetal, and spicy), two taste attributes (bitter and acid), and one mouthfeel attribute (overall astringency). Anthocyanins were high­er in Malbec and Petite Sirah monovarietal wines and blending/co-fermenting with these tended to increase anthocyanin content. Tannins were higher in Merlot and Petite Sirah monovarietal wines and cofermentation, and post-alcoholic fermenta­tion blending preserved more tannins than post-malolactic fermentation blending. The detailed chromatic composition of the wines was heavily determined by each monovarietal wine, with blending and cofermentation playing a much less relevant role on these parameters. The sensory data were analyzed with TDS curves and a tra­jectory principal component analysis. Preliminary sensory results found that while the different blending periods shared several attributes, the time of dominance differed. Co-fermentation and post-malolactic blending tended to show dominance earlier in evaluation than post-alcoholic fermentation blending. Additionally, each cultivar appeared to contribute to the dominance of certain attributes. Malbec was associated with the dominance of acidity, while Petite Sirah tended to influence the dominance of the spicy retro-nasal aroma and early perception of astringency.

Funding Support: E&J Gallo Winery