Nine Nevada County wineries will offer wine tastings and barrel samplings at one location during Saturday's second annual "Grape Affair."Burch Hall Winery, Indian Springs Vineyards, Iron Mountain Winery, Sierra Knolls Vineyards & Winery, Sierra Star Vineyards & Winery, Smith Vineyards & Winery, Double Oak Vineyards & Winery, Nevada City Winery and Lucchesi Vineyards & Winery will participate in the Nevada County Winery Association-sponsored event."We wanted everyone to get a chance to see us all, it's a great venue for wine tasting and to get a sense of the Sierra Foothills wine," said Julie Holmes, Indian Springs Vineyards tasting room and …