On a hillside high above the Douro River, Jerry and Carolee Luper pick the last of their Touriga Nacional. Soon these grapes will find their way into bottles of their superb red table wine, Quinta da Carolina, which may eventually make its way to the United States and, perhaps, even back home to California. It has been a long path to the Douro Valley from the campus of California State University, Fresno (once called Fresno State College), where they first met in 1972 as Jerry was completing his...