If you’ve ever sipped an $18 bourbon rocks at a classy tavern in South Florida, chances are good those rocks came from Mixology Ice. At his chilly warehouse northwest of Miami International Airport, Leal and his partner, Fabian Alvarez, pump out massive blocks of clear ice every five days. These icemen start with tap water, which flows through a five-step filtration system that peels away impurities. Once filtered, a $5,000 freezer called a Clinebell chills the water into two 300-pound blocks. Leal says that ice is then painstaking carved into Collins rods, chiseled into two-inch cubes and molded into spheres.