Review [source]:

The Bourbon Vertical Series is a unique opportunity to follow a group of 1,350 MGP bourbon barrels as they age from four to twelve years, and experience the arc of flavors throughout the nine-year journey. Every year, Pinhook selects 150 bourbon barrels from the lot and blends and proofs them to create the most balanced expression of the whiskey at that age. The Vertical Series began with the inaugural 4 Year release in 2019, and the journey continues through annual releases up to age 12.

With another year of maturation, the 6-Year Bourbon War showcases rich aromas of brown sugar, licorice and toasted almond. Subtle notes of smoke and honey exhibited by the 5-year vintage have developed into a full palate of black cherries, cloves, and Tahitian vanilla.