Ben and Laura Johnson started Duesterbeck's Brewing Company to save their multi-generational family farm. Their beer was just promoted from the farm to American Family Field. Their hefeweizen ale, Bees Be Crazy, is now available during all Milwaukee Brewers home games."We were just floored," Laura Johnson said. "What do you even say? We're just a farm, you know." The Johnsons started Duesterbeck's on their more than 150-year-old farm on County R…