A wine steward, also called a sommelier, is a restaurant professional whose sole responsibility is to keep track of and maintain the wine supply. Your job duties can also entail organizing a wine cellar and giving customers advice on what wine they should pair with their food, as certain types of wine pair best with certain meats or cheeses. You are usually employed at more expensive restaurants. To be a good wine steward, you need to be well-versed in tasting wine and be an expert in the wines being served.