Robert Parker "Friggin amazing #whiskey from Hillrock Estate Distillery!" Hillrock 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 the youngest cask in the solera is filled with new whiskey. As a result, no cask in the solera is ever fully emptied. In addition, as the younger whiskey ages and cascades through the solera, its average age and complexity gradually increases over time. Hillrock Solera Aged Bourbon marries Hillrock Estate Bourbon with a mature seed bourbon that was carefully sourced by Pickerell. After cascading through the solera, Hillrock Solera Aged Bourbon is finished in 20 year old Oloroso Sherry casks. The finishing process balances the spicy rye flavors of the bourbon and adds further complexity, with layers of fig, roasted walnuts and candied fruit. The current age of Hillrock Solera Aged Bourbon is over six years and the rye content is approximately 37%.