Bardstown Bourbon Company goes East for its latest Distillery Reserve release, Mars Single Malt Japanese Blend. Developed in collaboration with Japan’s Mars distilleries, this limited release represents a first-of-its-kind co-aging process, uniting tKentucky bourbon and Japanese whisky within a single barrel.
Japanese single malt whisky from Mars Komagatake and Tsunuki distilleries was shipped to Bardstown, Kentucky, where it was introduced into barrels containing mature bourbon. Rather than a traditional finishing approach, the Japanese whisky and Kentucky bourbon were aged together in-barrel, allowing the spirits to fully integrate and evolve, emerging 12 months later as one. The final year of aging allowed the products to develop and find balance together. The result is a 109.8 proof spirit.
The Japanese components—both crafted from 100% malted barley—bring distinctive character shaped by their original maturation. Komagatake single malt, aged in Umeshu (plum liqueur) barrels, contributes rich fruit and floral complexity, while Tsunuki single malt, aged in rare Sakura (cherry wood) barrels, imparts delicate spice and subtle wood influence. Aged together with a foundation of Kentucky bourbons aged 10 and 16 years, the end result is a layered and globally inspired whiskey unlike anything else.
“This project is about more than blending—it’s about true integration,” said Bardstown Bourbon Company Master Blender Dan Callaway. “By aging Japanese single malt whiskies together with Kentucky bourbon in the same barrel, we’ve created something entirely new. The result is a seamless conversation between two traditions, where neither overpowers the other, and both are elevated.”
“We are hopeful that this collaboration will open up new possibilities in the art of whiskey-making,” added Kazuto Hombo, President of Hombo Shuzo Co, makers of Mars Whisky. “By fusing the techniques and philosophies each company has cultivated, and by utilizing carefully selected base whisky, aging environments, and delicate blending techniques, we aim to create a new whiskey experience that combines depth and elegance. ”
Launched in 2025, Bardstown’s Distillery Reserve is a platform for small-scale innovation, offering one-time-only releases that challenge the boundaries of whiskey through experimental finishes, extended aging, and uncommon blending. Prior releases including Cathedral French Oak, Hokkaido Mizunara Oak and Normandie Calvados Brandy Barrel, and Cascadia Garryana Oak.
A second innovation blending Japanese and American whisk(e)y traditions is currently underway at Mars’ Tsunuki Distillery, in the southern region of Japan. The Mars blend also combines Bardstown Bourbon whiskey with their own aging stock.
“Through this initiative, we intend to deliver unprecedented taste to our customers by respecting tradition while embracing innovation,” Hombo said. “While it will take a little more time, we are eagerly anticipating the results of this unique endeavor.”
Bardstown Bourbon Company’s Distillery Reserve Mars Single Malt Japanese Blend is available exclusively at Bardstown Bourbon Company’s distillery gift shop and its Tasting Room in Louisville for $99.99
