A few months ago, a 2010 recipe for ice cubes on Food.com went viral. Actually, it wasn't the recipe, which was posted as an amusingly passive-aggressive attack on those who forget to fill empty ice-cube trays, that went viral so much as the comments several hundred in-on-the-joke variations ("a touch of salt is so important") and gripes ("the coldness kind of takes away from the flavor"). Truth is, though, for the serious cocktail set, ice is no laughing matter: The perfect ice cube must be as clear and pure as possible; it must chill the drink while minimizing dilution. Over the past couple of years, the cream of the local mixology crop has been employing ice far more pure than what comes out of your freezer at home to achieve these aims. Several bars now rely on the cubes from machines manufactured by Erie, Pennsylvania-based Kold-Draft, solid blocks of ice so well filtered they are essentially transparent. Ted Kilgore of Taste uses Kold-Draft ice, but for certain drinks he employs a single cylinder of ice roughly as big as a baseball. And, no, the Food.com recipe won't produce these incredible read-the-date-on-a-dime clear cylinders. Kilgore gets them from Ice Visions, the Kirkwood-based company of ice sculptor David Van Camp.