Blair Walter understands his vineyards and wines more intimately than anyone I know in Central Otago, and it’s rare for him to be lost for words in explaining anything. Yet even he can’t account for the unprecedented mineral expression of Block 1 in the pristine 2012 season. This is a riesling at once deeply chalky, mineral and textural, and at the same time taut and refined, with a minerality that resonates with the deep, glacial soils of this unique site. Sweetness and high-tensile acidity have an engaging tussle on the finish, with neither winning out. A clean lemon and lime profile is overlaid with pristine perfume of lemon blossom and a delicately fragrant lift, while a hint of pepper adds another dimension to a finish that never seems to end. The finesse, persistence and sheer purity of this wine rank it among the finest Block 1s of all time. $44 at Armadale Cellars.