Eleven years ago, Stefan Vetter was home celebrating the Christmas holiday with his family in Germany’s Franken region when he opened the local newspaper to a page advertising a lease on a small 50-year-old sylvaner vineyard in nearby Casteller Kirchberg. Most winemakers would be forgiven if they blew past the posting. After all, sylvaner is a grape whose common descriptor is “nondescript.” Even in Franken, where sylvaner is the white grape, a half-century-old vineyard isn’t the kind of commodity it might be in most of the world’s top winemaking regions. But in this rare old plot of vines, Vetter saw an opportunity…..