In search of the taste of terroir – a challenge for sensory science

The definition of terroir has evolved throughout history, from something clearly negative in the XVIth-XVIIIth century to a complex multi-parametric construct with positive connotations but also with many scientific unknowns. Terroir has always been linked more or less explicitly to the sensory properties of the resulting products.

Wine consumers have little access to objective terroir information and even if they had, it would be very difficult for them to interpret in terms of wine quality. In Europe, the proxy for terroir is the Protected Designations of Origin (PDO) system, which is what consumers have come to know. According to INAO “It is the notion of soil (terroir) that is the basis of the concept of Appellations d’origine” and results in a product with original and typical features.

From a cognitive point of view, terroir-based and other wine sensory categories have been approached from prototype categorization theory, according to which categories are stored in long-term memory as prototypes. The prototype would be abstracted from the instances of the category during previous tastings and shared between experts. The prototype is highly typical of the category and serves as reference to categorize new items. Such categories are based on family resemblance (instances from the same category share more features then instances from different categories) and are organized according to a typicality gradient.

The main sensory methods used to explore the structure of wine sensory categories are typically ratings and sorting tasks combined with descriptive analysis. The sensory studies dealing with PDO-based categories are scarce. Globally, the results suggest that PDO-based categories are quite difficult to distinguish sensorially. A possible explanation is that high within-category variability makes it difficult to pinpoint a prototype and yields quite fuzzy borders.