Turning A Bordeaux Into a Grand Cru Classé Formula 1 Wine

How many times have you heard, "Great wines are made in the vineyard."? (Zzzzzzzz.) Michel Rolland, the famous, and famously controversial, wine consultant, speaking to Harper's, shares an interesting metaphor regarding what the land gives and what the winemaker takes. "The greatest wines are like Formula 1," he begins. "Their performance is linked to the terroir first--people have a relatively low influence on the outcome, however, those who make adjustments successfully are those who wine the race."

So is it just the consultant making a few tweaks that culminates in a victorious wine? Or is it a collaboration between the two that gets results? What is the relationship between winemaker and consultant?