Instead of leaving annual volume loss to the angels, Bardstown Bourbon Company has found a way to fill the empty space in its latest Distillery Reserve. 

Distillery Reserve Mars Single Malt Japanese Blend, a pioneering release that bridges Kentucky bourbon and Japanese whisky traditions in an entirely new way, is available in extremely limited quantities beginning May 29, 2026. Developed in collaboration with Japan’s Mars distilleries, this limited release represents a first-of-its-kind co-aging process, uniting two distinct whisky cultures 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. It also added additional wood sugar and barrel character after a warm Kentucky summer. 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,” Dan Callaway, Master Blender, Bardstown Bourbon Company, said in a news release. “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,” Mr. Kazuto Hombo, President of Hombo Shuzo Co, makers of Mars Whisky, said. “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.” 

“We are hopeful that this collaboration will open up
new possibilities in the art of whiskey making.”
-Mr. Kazuto Hombo

Distillery Reserve Mars Single Malt Japanese Blend is presented at 109.8 proof (54.9% alc. by vol.) and sold for $99.99 in the Distillery Reserve’s signature 375mL format. The Distillery Reserve is available exclusively at Bardstown Bourbon Company’s distillery gift shop and its Tasting Room in Louisville. 

Launched in 2025, the 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, have been praised by critics and consumers alike as stand-out whiskeys that reinforce Bardstown’s reputation for bold innovation. 

A second innovation blending Japanese and American whisk(e)y traditions is currently under way at Mars’ Tsunuki Distillery, in the southern region of Japan. The Mars blend also combines Bardstown Bourbon whiskey with their own aging stock. 

Mr. Hombo added, “Through this initiative, we intend to deliver unprecedented taste to our customers by respecting tradition while embracing innovation. While it will take a little more time, we are eagerly anticipating the results of this unique endeavor.” 

Read more: Bardstown Bourbon Distillery Reserve Returns with Unique Barrel Finish

ABOUT BARDSTOWN BOURBON 

With a modern, technically advanced whiskey distillery, Bardstown Bourbon combines high quality distillation and spirited hospitality into a modern, authentic bourbon experience unlike any other on the Kentucky Bourbon Trail. Bardstown Bourbon Co. is working to push the entire industry in a direction that is more innovative, more transparent and more collaborative. For more information visit BardstownBourbon.com.