Blade and Bow Kentucky Straight Bourbon is crafted using a solera-aging, a process typically reserved for aging cognacs, ports and sherries. This is done to preserve the precious original stock of Stitzel-Weller, which is mingled with other fine whiskies during the solera process, during which a series of casks are filled at different intervals over a long period of time (in fact, Blade and Bow Kentucky Straight Bourbon contains the oldest remaining stock of whiskey distilled at Stitzel-Weller, and will be the last available liquid for sale that was distilled at the original distillery). As whiskey from the oldest cask is emptied and bottled, the cask is refilled 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 increase over time.