Which of these is a trained and knowledgeable wine professional?
A sommelier, or wine steward, is a trained and knowledgeable wine professional, normally working in fine restaurants, who specializes in all aspects of wine service as well as wine and food pairing. The role in fine dining today is much more specialized and informed than that of a wine waiter. Sommeliers Australia states that the role is strategically on par with that of the chef de cuisine.
A sommelier may be responsible for the development of wine lists, and books and for the delivery of wine service and training for the other restaurant staff. Working along with the culinary team, they pair and suggest wines that will best complement each particular food menu item. This entails the need for a deep knowledge of how food and wine, beer, spirits and other beverages work in harmony. A professional sommelier also works on the floor of the restaurant and is in direct contact with restaurant patrons. The sommelier has a responsibility to work within the taste preference and budget parameters of the patron.
In modern times, a sommelier's role may be considered broader than working only with wines, and may encompass all aspects of the restaurant's service, with an enhanced focus on wines, beers, spirits, soft-drinks, cocktails, mineral waters, and tobaccos.