A sommelier is a person who specializes in all aspects of wine service and is a knowledgeable wine professional. They manage the wine service in restaurants, country clubs, distribution firms, etc. They are able to specify the region of origin and describe the characteristics of wines based on its taste. They can detect a wine's distinctive ingredients, but it is not due to having sensitive palates. Recent brain scans of sommeliers revealed that as they taste wine, their brains react differently from those who are inexperienced in the field. When sommeliers take a sip of wine, the brain shows greater activity in regions associated with the functions of memory, language and decision making. These findings are consistent with what is already known about the true specialized skills of sommeliers. They have developed a rich understanding in language to describe the taste and smell of wine. Their extensive practice in describing the sensory effects of these components is what leads to their expertise in categorizing the different production dimensions of wine. Although extensive practice can help describe the characteristics of wine, these experts have explicit knowledge which makes it much easier for them to categorize and then remember meaningful constellations of flavor. Overall, sommeliers do not have greater sensitivity in their tongues and noses, but instead their skills are based on learned conceptual knowledge, attention to flavor configurations, and language use.
Rosenblum, L. D. (2011). See what I'm saying: the extraordinary powers of our five senses. W.W. Norton.