Investigating impact of terroir on sensory perception of wines made from hybrid grape cultivar ‘Marquette’

Abstract

In this study we investigated the impact of geography, soil type, and harvest date on grape quality traits (e.g., cluster development, cluster architecture, fruit quality, and wine quality). The hybrid variety ‘Marquette’ was planted at six locations in Minnesota (4 locations) and North Dakota (2 locations). Grapes at each location were harvested on three different dates during two subsequent years (2019 and 2020). Growing degree days at harvest varied across sites from 1963 to 2661 units in 2019 and 1818 to 2584 units in 2020. Standard quality data including grape size, juice and wine chemistry, and cluster images were collected. Additionally, a sensory study was conducted in 2024 with 29 identically produced ‘Marquette’ wines, using a Latin-square design evaluated by 25 panelists from the local wine industry. Panelists calibrated their palates with a serial dilution of citric acid standards, then ranked six wines for aroma and flavor traits on a sliding intensity scale from 0-20. Significant variation for berry, juice, and wine traits were observed across sites. ’Marquette’ juice titratable acidity ranged from 8.88 g/L to 14.45 g/L and soluble solids content ranged from 18.6 to 26.7 °Brix.  Panelists also reported an overall pleasing experience of the ‘Marquette’ wines, with varying perception of both positive (floral, fresh fruit, etc.) characteristics and negative (astringency, cooked vegetable, etc.) traits among wines from different sites. These results will inform new recommendations about best practices for harvest decisions in each location, rather than more general regional recommendations.