One interesting footnote is that Spanish production of tradition method sparkling wines was triggered by the Phyloxera plague of the late nineteenth century. The Champagne region was decimated and French negotiants went south in search of a replacement product, which they actually labeled as Champagne. With the advent of European Union regulations, the Spanish product could no longer legally be called Champagne, hence the creation of the name Cava, but like anywhere else many people not in the trade still use Champagne as a catch-all term for bubbly.
Question: Isn't the Jerez D.O. also akin to the Cava D.O. in that it limits wineries to production of a particular category of wines, in this case Generosos, or fortified wines?