(Timesdispatch) - Greg Pugh poured a taste of Sweet Cherry into the cluster of outstretched wine glasses. "The first taste is tart," he cautioned. "On the second taste, the sugar comes to the surface." Then it was on to Dragon's Blood, a bright red pomegranate melomel from Hill Top Berry Farm & Winery, one of about 75 wineries offering tastings this weekend at the fifth annual Virginia Wine Expo. With more than 450 types of wines from big-name wineries to niche labels, the expo drew thousands to the Greater Richmond Convention Center — about 4,500 had been through the turnstile just four hours after doors opened Saturday.