Linking the Sensory Properties of Chardonnay Grape Vitis vinifera cv. Berries to Wine Characteristics

Abstract

Formal or informal sensory analyses of grapes are often used to determine when a parcel of fruit should be harvested to produce a certain wine style. This study investigated whether relationships exist between sensory perceptions and basic chemical measures of Chardonnay grape berries and the corresponding wines. Chardonnay grape parcels were harvested at commercial maturity from across South Australia in vintages 2015 and 2016, yielding a total of 25 and 24 samples, respectively. Grapes were evaluated using berry sensory assessment (BSA) and vinified identically using small-scale winemaking, and the resulting wines were evaluated with descriptive sensory analysis. Sensory assessors were trained in the respective sensory evaluation methods. Chardonnay grape and wine samples were discriminated by the panel according to sensory attributes, and the fruit could also be discriminated by basic chemistry measures. However, differences in Chardonnay wines were subtle compared with those in grapes, as indicated by low effect sizes. Moderate validation models (R²_Val = 0.53 to 0.81) of partial least squares regression (PLSR) 1 were determined in the 2015 vintage, using BSA attributes as x-variables and wine sensory attributes as y-variables, but poor models were obtained with the 2016 vintage (R²_Val < 0.5). In the 2015 models, relationships were found for wine attributes of heat, sourness, and astringency, possibly due to slight variations in ripeness. Strong relationships that revealed wine style from variations in grapes were not found. Overall, relating the sensory characteristics of Chardonnay grapes to the wines was challenging and indicated that variation in style of these varietal wines does not greatly depend on the raw grape material.