By JIM FAIR A Travelers Rest brewery won a silver medal in the Bock beer category at the Great American Beer Festival held in Denver earlier this month. Numbskull, brewed at the Swamp Rabbit Brewery & Taproom, won the silver medal from among 36 entries in the bock category. Bock beer is a rich, complex, malty, low-hop style of lager, according to websites describing the basic taste. The only other South Carolina winner was Charleston’s Revel Brewing Co., with a silver medal for Oh My Darlyn! in the Scotch Ale category. There were 286 medals awarded to some of the best commercial breweries in the U.S. at the 30^th annual festival. Judges were assigned beers to evaluate in their specific area of expertise and never judged their own product.