“Brett character” in wine: Is there a consensus among professional assessors? A perceptual and conceptual approach

• We investigate perceptual and cognitive skills that affect wine quality assessment.
• We use different psychophysical tests.
• Expertise could lead to variations in the assessment of off-odor.
• Olfactory experiences modify decision processes and behavior of wine professionals.

Ethylphenols are micro-organism-derived compounds that contribute to the Brett character in wine. These chemicals give off characteristic odors, associated with descriptors such as phenolic, pharmaceutical, stable, leather, and horse. Their organoleptic impact on wine is a recurring debate among wine professionals. However, links between these compounds and an attenuation of fruity and varietal aromas in wine have been demonstrated, while several studies have highlighted the poor correlation between ethylphenol concentrations and the perception of Brett character. These variations in assessment may be explained by several perceptual factors. This article presents an investigation of perceptual skills and socio-professional parameters that affect ethylphenol assessment. As tasting performance relies on both perceptual skills and a decision-making process, several psychophysical tests (detection threshold, description task, and the Signal Detection Theory methodology) were used to assess the impact of socio-professional parameters on olfactory capacities and strategic/decisional factors. The hypothesis that expertise, in terms of age and qualifications, had an impact on the assessment of Brett character was confirmed.