Hillrock Solera Aged Bourbon 750Hillrock Solera Aged Bourbon is the world's first solera aged bourbon. Solera aging is a process that has generally been reserved for aging cognacs, ports and sherries. It involves filling a series of casks at different intervals over a long period of time. As whiskey from the oldest cask is emptied and bottled, the cask is re filled with an equivalent amount of whiskey from the second oldest cask in the solera. This cascading effect continues until