By Sasha Smith, New York City Correspondent Photo by Sasha Smith A few weeks ago I attended the first annual Winebow "I Drink New York" event at Astor Wines featuring Ravines Wine Cellars, Wolffer Estate Vineyards and Millbrook Vineyards. I focused on Ravines, which I knew little about (aside from the fact that Lenn's a fan) and Wolffer. A brief dispatch: A good wine is like a good thriller: it should hold your attention throughout and finish with a surprise. The Ravines Wine Cellars 2007 Dry Riesling fulfilled both criteria. The wine has a mineral and citrus fruit purity that’s…