(WSJ) - It was raining as I approached Barsac, the small village at the heart of France's sweet-winemaking region. Navigating my car along its tiny back roads, I had long since given up on my GPS, which insisted I had "reached my destination," though I was clearly still far from where I was supposed to be: in the cellars of Château Climens, one of the appellation's leading properties. Trusting my instincts, I took a right at the fork, drove over a train track and, with just one call to the château, managed to find my way onto its expansive gravel drive, the rain still pouring.