Australia’s iconic winery, Penfolds—which celebrates its 170th anniversary this year and is perhaps best known for its highly collectible Grange Shiraz—is conducting a series of free recorking clinics for owners of Penfolds red wines that are more than 15 years old. These clinics, the only hands-on collector’s service of their type offered by a winery, are held annually in various countries. This year, Penfolds’ chief winemaker, Peter Gago, and a colleague will conduct just two recorking clinics in the United …