Soil types as extrinsic cues differentially shape sensory perception of German Riesling wine

Despite the lack of consensus regarding the effects of different soils on wine flavour, the simplification of terroir to soil type has become increasingly common in wine marketing, particularly for German Riesling. To examine the effects of this strategy on sensory perception, twenty German Rieslings from four commonly marketed soil types (Buntsandstein, Löß, Muschelkalk, and Schiefer) were evaluated for aroma, taste, and mouthfeel attributes (rate-all-that-apply) by a panel of twenty wine experts, first without and then with each wine’s soil type given as an extrinsic informational cue. While ratings from the uninformed tastings suggest baseline differences among Rieslings from the various soils, the provision of soil type cues resulted in more extensive discrimination, particularly in terms of attributes related to minerality (earthy, chalky, marine, flinty, and salty). Soil type-dependent changes in ratings suggest distinct a priori conceptions for each soil shaped the panel’s expectations and differentially altered their perception, though further work is needed to determine whether nonexpert consumers would be similarly biased by these cues. For wine soil typing to be a viable marketing strategy, a well-defined “image” of each soil would need to be communicated to consumers, to ensure their expectations are set to trigger perception of the desired sensory properties.