It happens almost every time. American oak comes up in a conversation, and I see it: that subtle flinch, a pinch of the lips, maybe a cocked eyebrow. As a subject, American oak seems to be forever filed away under “things sommeliers know they hate.” And yet, this hypothetical person, our imagined skeptical sommelier, would likely never turn down a glass of López de Heredia, well-aged Grange, Ridge Monte Bello, or Pappy…