Napa luxe

What is the defining characteristic of a wine region? The answer depends on who you ask, of course, but typical responses often range among the many distinctive aspects of the wine world: geology, topography, oenology, or even culture. The Mosel has its steep slate soils, Châteauneuf-du-Pape has its distinctive blend of 14 grapes, Chile’s Maule Valley has its twisted old vines of País and Carignan. And what of California’s Napa Valley? Beyond an affinity for Cabernet Sauvignon, an argument could convincingly be made that Napa has become known simply for luxury.

Perhaps this is why the recent news that Colgin...