Descriptive analysis of Frontenac gris and Brianna wine grape and wine varieties

Abstract

Interest in producing cold-hardy wine grape cultivars has developed over the past few years, and Frontenac gris and Brianna are two such cultivars that have recently been released by the University of Minnesota breeding program. The first objective of this study was to describe the aroma and flavor attributes of Frontenac gris and Brianna wine grapes and wine and to determine how the ripening process affects changes in sensory attributes of the grapes and their respective wines. The second objective was to develop a set of descriptors that define aromas and flavors of Frontenac gris and to determine whether each of these descriptors are perceived in a majority of Frontenac gris wines. For the first objective, wine grapes and wines from one winery in South Dakota were evaluated over different harvest dates. For the second objective, 19 Frontenac gris wines from various wineries were evaluated. For both objectives, members of the trained panel from the Sensory Center at the University of Minnesota learned a standardized technique to taste wine grapes and/or wine and developed a lexicon of flavors and aromas occurring in these grapes and wines. Panelists participated in testing sessions during which they rated the intensity of the attributes in each of the grapes and in each of the wines. As Brianna grapes ripened, they increased in fermented fruit, artificial grape, and sweetness, and decreased in sourness, bitterness, citrus flavor, and green apple flavor. The following attributes increased in intensity with progressively later harvest dates for Brianna wine: mushroom, soy sauce, sauerkraut, corned beef, and sweetness. The following attributes decreased in intensity with progressively later harvest dates for Brianna wine: sourness, fresh raspberry, fresh grapefruit, and green apple. As Frontenac gris grapes ripened, the grapes decreased in the dried grape flavor attribute. For Frontenac gris wine, the fresh grapefruit aroma increased in intensity and then decreased in intensity with later harvest dates. Attributes found to define 75% or more of the Frontenac gris wines were dried apricot aroma & flavor, dried cherry aroma & flavor, citrus fruit aroma & flavor, dried fruit aroma & flavor, fresh strawberry aroma & flavor, green wood aroma & flavor, fresh green flavor, canned peach aroma, and canned pineapple flavor. Paired with information about the chemical maturity of the Frontenac gris and Brianna grapes, this knowledge will improve determination of the ideal maturity of the wine grapes for maximizing the overall quality of these wines. Also, paired with information about location, yeast, residual sugar, and alcohol percentage, wineries can decide which of the defining attributes of Frontenac gris they want to be dominant in their wines.