Move over merlot, make room for some little-known grape varieties such as tempranillo that are gaining ground in El Dorado County. The county’s winemakers are adding these varieties to boost business and create more of a niche in the premium wine market. They are bottling Grenache as a stand-alone variety. And they are grafting obscure red winegrape vines to well-known whites. The county produced a wine-grape crop valued at $5 million last year, small compared to other much-larger regions such as Napa and Sonoma. But the county’s wineries attract tourists with a $200 million economic impact to El Dorado County. Winemakers hope that premium wines will lure more of those tourists and boost business. This is Ron Trujillo for the Business Journal.