Longtime friends and oenophiles Rajat Parr and Jordan Mackay have had countless conversations about varietals and vintages, and constantly field questions from curious neophytes and savvy industry insiders about what makes a wine great. In an attempt to dispel the mysteries surrounding their profession, the two co-wrote "Secrets of the Sommeliers: How to Think and Drink Like the World's Top Wine Professionals," (Ten Speed Press) being published this month.