Most wineries on the East End of Long Island like to talk about being “sustainable” in their vineyard practices and winemaking. There’s discussion about windmills and compost piles and this spray or that application, but let’s be honest, “sustainable” is a nebulous term… at least in the way they are using it, to denote a certain “green”-ness without formal biodynamic or organic certification. Those require strict adherence to defined rules over a set period of time. “Sustainable” is a bit of a “green” grey area without any local definition or certification. It is a term that is decidedly open to interpretation.…