As the technical director and head enologist at “Avignon Oenologie Conseil,” Xavier oversees winemaking at more than 300 estates, including many of the best-known domaines in Châteauneuf-du-Pape. In lieu of payment for his laboratory’s service, he sometimes accepts wine, which “Xavier Vins,” the micro-négociant company he established in 2002, finishes and bottles.

Originally a physical chemist, Xavier is particularly interested in how the spectrum of dissolved mineral salts in the groundwater of each vineyard, which varies from parcel to parcel, influences the expression of terroir in the grapes. “I’m a trained enologist,” he says. “I’ve examined wine down to the molecular level. Which, in the end, convinces me that what is most important are the vines, the depth of the roots, and the health and balance of the vineyard.”