Comparison of different scaling techniques for sensory analysis of wines

The use of sensory analysis for the winemaking industry is an interesting tool for objective evaluation of wine quality. Its development forces us to properly define and to adapt the methodology of tasting to this particular product – wine. The development of methodology of sensory analysis adapted to the wine industry constitutes one of the objectives of research carried out by the team of research from the laboratory GRAPPE of ESA (Ecole Supérieure d’Agriculture of Angers) in collaboration with Interprofession of the Wines of the Loire. The influence of scaling techniques on sensory evaluation results was studied during the setting up of a wine sensory trained panel and in order to obtain objective and pertinent characterisations of wine. Three different scales were used : a 10-point category scale ; a line scale consisting of a line where each taster’s appreciation is converted to a mark between 0 and 10 ; a scale mixing the first two. For each scale, five red wines from different appellations of Val de Loire – France were tested by the wine trained panel of the Laboratoire GRAPPE. Each set was repeated once. The products discrimination was better with the line scale and the category one. Nevertheless, interactions between judges and products were higher with the first. Results were less satisfactory with the category line scale. This method seemed to be less discriminating and interactions were more important. This fact can be explained by the different use of the scale by tasters. This study enabled us to verify the impact of the number of wine tested in the same session. Indeed, some attributes were significantly higher for the repeated wines. These results might justify establishing a different order of passage of wine for each assessor, thus minimising the order effect. This experimentation opens interesting perspectives for the optimisation of sensory analysis methodology in the winemaking industry. Complementary studies are taking place in the Laboratoire GRAPPE.