Mars Shinshu, officially the Mars Komagatake Distillery, is a whisky distillery in Nagano Prefecture run by the shochu maker Hombo Shuzo (本坊酒造). Sitting at an elevation of around 798 meters at the foot of Kiso Komagatake in Japan’s Central Alps, it is the highest whisky distillery in the country, and its cold mountain climate and soft, granite-filtered water are central to how the distillery describes its own whisky. Mars Shinshu is also one of the few Japanese distilleries with a genuine gap in its production history: it stopped distilling entirely for nearly two decades before restarting in 2011.
That restart, and the distillery’s connection to one of the founding figures of Japanese whisky, make Mars Shinshu a useful case study alongside our guide to the Japanese whisky labeling standard, since its stills and methods trace back further than most currently operating distilleries in Japan.
History: a 1949 license, a false start, and a 2011 restart
Hombo Shuzo, a shochu producer originally from Kagoshima Prefecture, obtained a whisky-distilling license in 1949 with help from Kiichiro Iwai (岩井喜一郎), an engineer whose still designs, based on records left by Masataka Taketsuru (竹鶴政孝), also influenced Nikka’s Yoichi distillery. Hombo built its Shinshu Distillery in Nagano Prefecture in 1985, moving pot stills that Iwai had designed for an earlier Hombo distillery in Yamanashi to the new mountain site, where they have since been replaced with exact replicas of the originals.
That connection runs deeper than a shared engineer’s name. Iwai and Taketsuru first worked together at Settsu Shuzo, a major Osaka alcohol producer, where Iwai was Taketsuru’s senior colleague and, in effect, his boss. It was Settsu Shuzo’s own ambition to move seriously into whisky that sent Taketsuru to Scotland to study distilling in the first place; when he returned, he handed his handwritten training report, since known as the Taketsuru Note, to Iwai. Settsu Shuzo’s whisky plans stalled and neither man built a distillery there. Taketsuru went on to found what became Nikka. Iwai’s route took longer: he became an advisor to Hombo Shuzo in 1950, and when the company moved into whisky production in earnest at its Yamanashi plant in 1960, it was Iwai, drawing on the same Taketsuru Note he had been handed decades earlier at Settsu Shuzo, who produced the design for the stills. That is the specific thread linking Mars Shinshu’s pot stills to Yoichi’s: not a shared owner or a joint venture, but one engineer applying the same borrowed research to two unrelated companies’ equipment years apart.
The distillery’s history was not continuous. Production stopped in 1992 as demand for Japanese whisky slumped through the 1990s and 2000s, a period that closed or paused output at several Japanese distilleries. Mars Shinshu resumed distilling in 2011, as the global reappraisal of Japanese whisky began driving renewed investment across the industry, making it one of a small number of distilleries that can describe their current output as a genuine restart rather than continuous production.
The numbers behind that closure explain why it happened only seven years after the Shinshu site opened. Japan’s whisky market had already peaked in 1983 and kept shrinking for roughly 25 straight years, a decline that didn’t reverse until whisky-and-soda promotions helped revive demand from 2008 onward. Hombo built its Nagano distillery in 1985, two years into that downturn, and by 1992 was sitting on aging stock it could not sell fast enough to justify distilling more. The decision was narrower than it can sound in hindsight: Hombo kept selling whisky from existing stock and never exited the category outright, which is part of why restarting in 2011 was a matter of resuming production rather than rebuilding a business from nothing. The 2011 restart followed the same commercial logic in reverse, timed to the recovery in Japanese whisky demand rather than to any change in the distillery’s site or equipment.
That gap matters for how readers should think about the brand’s back catalog. Whisky bottled or distilled before 1992 comes from a genuinely different production era than anything released after the 2011 restart, with nearly two decades separating the two. Collectors and reviewers often treat pre-1992 Mars Shinshu releases as a separate, older category from the current Iwai and Komagatake lines, in much the same way that whisky from other paused-and-restarted distilleries tends to be discussed in two distinct chapters rather than as one unbroken lineage.
What Mars Shinshu makes: high altitude, old still designs
The distillery’s site was chosen deliberately for its environment: soft water filtered through granite soil, meltwater from the surrounding Alps, and consistently cool, foggy mountain air at nearly 800 meters above sea level. Hombo describes this high-altitude, low-temperature setting as a defining influence on how the spirit matures, distinct from the warmer, lower-altitude conditions most Japanese distilleries operate in.
That contrast with warmer conditions isn’t incidental to how Hombo runs the business; it’s the point. The company operates two whisky distilleries and a separate maturation cellar, each in a deliberately different climate: Mars Shinshu, now renamed Mars Komagatake, at 798 meters in the Central Alps; Mars Tsunuki back in the company’s original home of Kagoshima, at low altitude and far warmer temperatures; and an aging cellar on the subtropical island of Yakushima. Hombo states that its aim is to pursue what it calls its own distinct quality through harmony between different natural environments and technique, treating climate as a variable used deliberately across sites rather than a condition to correct for at a single one. Cooler, slower maturation at altitude in Nagano and faster, more tropical aging in Kagoshima and on Yakushima are, on the company’s own account, two different tools feeding the same broader blending program rather than two competing house styles.
Its pot stills carry that history forward physically rather than just in name. Designed by Kiichiro Iwai using Masataka Taketsuru’s own production notes, they closely resemble the straight-head stills used at Nikka’s Yoichi distillery, meaning Mars Shinshu’s still shape traces back to the same technical lineage as one of Japan’s oldest and most established whisky producers, despite Mars Shinshu’s own broken production history.
The original stills Iwai designed were first installed at an earlier Hombo distillery in Yamanashi Prefecture before being relocated to Nagano when the Shinshu site opened in 1985. They have since been replaced with exact replicas rather than kept in continuous service, which means the equipment working today reproduces Iwai’s original engineering rather than being the literal decades-old metal, a distinction worth noting for readers who assume every detail of a distillery’s founding-era hardware survives unchanged.
Core bottles and what they taste like
Mars Shinshu’s range splits into blended and single malt lines. Iwai, sold with a blue label, is the entry-level blend, with a nose of cinnamon and brûléed sugar leading into a palate of Red Delicious apple skin and English breakfast tea. Iwai Tradition sits above it, opening with clove and wildflower honey alongside a hint of earthy peat, moving into nougat and milk chocolate on the palate, with cinnamon rejoining on the finish. Komagatake is the distillery’s single malt line, released in dated annual editions rather than as one fixed, unchanging bottling.
At the World Whiskies Awards 2025, Mars Komagatake Japanese Barley 8 Years Old won a Bronze award, a specific, dated result rather than a general claim about the brand. Separately, at the 2022 San Francisco World Spirits Competition, the Komagatake 2021 Edition was among the whiskies in contention for Best of Class Japanese Whisky, in the same field as Kanosuke’s 2021 First Edition Single Malt.
| Expression | Type | Notable result | Flavor profile |
|---|---|---|---|
| Iwai (Blue Label) | Blended whisky | Entry-level core release | Cinnamon and brûléed sugar on the nose; Red Delicious apple skin and English breakfast tea on the palate |
| Iwai Tradition | Blended whisky | Step-up core release | Clove, wildflower honey, and a hint of earthy peat; nougat and milk chocolate with cinnamon on the finish |
| Komagatake (annual editions) | Single malt | Japanese Barley 8 Years Old won Bronze, World Whiskies Awards 2025 | Varies by edition; profile not fixed across releases |
For readers deciding what a bottle of Komagatake or Iwai represents, the story behind Mars Shinshu is less about one continuous tradition than about two separate commitments stacked on top of each other: an engineering lineage borrowed from Taketsuru’s own research notes by way of Iwai, and a present-day strategy of maturing spirit at deliberately different altitudes and climates across Hombo’s three sites rather than settling on one. The nearly two-decade gap in production is part of that story rather than a footnote to skip past, since it means today’s Komagatake releases represent a genuinely restarted operation still rebuilding its own aged stock, not a seamless continuation of what Iwai’s stills produced in the 1980s.
Can readers outside Japan buy it or visit?
Mars Shinshu is more accessible abroad than many small Japanese distilleries, largely because Hombo Shuzo has worked with established importers for years rather than relying solely on direct export. In the United States, Skurnik Wines & Spirits and Tokiwa Imports both carry parts of the range, including several Iwai Tradition cask-finish variants, which puts entry-level and mid-tier Mars Shinshu bottlings within reach of readers outside Japan more reliably than is the case for some of the newer, smaller distilleries covered elsewhere on this site. Limited-edition Komagatake releases are harder to find and tend to sell through allocations rather than open retail, so readers chasing a specific annual edition should expect more competition for stock than with the Iwai line.
Visiting requires planning around geography and season. The distillery sits in a mountain location in Nagano Prefecture, at the foot of Kiso Komagatake, and its visitor building sells distillery-exclusive whisky, Mars wine, Minami-Shinshu beer, and original goods alongside displays of past releases and awards. Because the site is high-altitude and mountainous, tours and visiting hours are seasonal rather than year-round, so readers should confirm current opening dates and hours directly with the distillery before building a trip around a visit, particularly outside the warmer months.
FAQ
Q: Why did Mars Shinshu stop making whisky for almost 20 years?
A: Production halted in 1992 as demand for Japanese whisky fell sharply through the 1990s and into the 2000s, a downturn that affected the wider industry and led several producers to pause or scale back distilling. Hombo Shuzo resumed whisky production at Mars Shinshu in 2011, as renewed international and domestic interest in Japanese whisky made restarting commercially viable again. That gap means older Mars Shinshu stock and post-2011 releases come from genuinely separate production eras rather than one continuous run.
Q: What is the connection between Mars Shinshu and Nikka’s Yoichi distillery?
A: Mars Shinshu’s pot stills were designed by Kiichiro Iwai, an engineer who based his still designs on production records left by Masataka Taketsuru, the same person who later founded Nikka and built the Yoichi distillery. As a result, Mars Shinshu’s stills closely resemble the straight-head design used at Yoichi, even though the two distilleries have always been run by separate, unrelated companies with no ownership connection to one another.
Q: Is Mars Shinshu whisky easy to find in the US or UK?
A: The entry-level Iwai and Iwai Tradition blends are reasonably accessible through established importers such as Skurnik Wines & Spirits and Tokiwa Imports in the United States, which makes them easier to find than output from some of Japan’s smaller, newer distilleries. The single malt Komagatake line, released in limited annual editions, is considerably harder to source and tends to move through allocation rather than staying on general retail shelves for long.
Q: What makes Mars Shinshu’s location unusual for a whisky distillery?
A: At roughly 798 meters above sea level at the foot of Kiso Komagatake in Nagano’s Central Alps, it is the highest whisky distillery in Japan. The site gives the distillery soft water filtered through granite and consistently cool mountain air, conditions Hombo Shuzo says shape how the spirit matures, in contrast with the lower-altitude, warmer environments most Japanese distilleries operate in. The altitude also means visiting hours run on a seasonal schedule rather than year-round.
Sources
- HOMBO Official, “Mars Komagatake Distillery: Visiting Experience” — hombo.co.jp
- HOMBO Shuzo (official), “沿革” [Company History] (Japanese) — hombo.co.jp
- HOMBO Shuzo (official), “ウイスキー品質へのこだわり” [Whisky quality] (Japanese) — hombo.co.jp
- WHISKY Magazine Japan, “信州マルス蒸溜所 蒸溜釜更新” (Japanese) — whiskymag.jp
- note (Charlie / Whisky Diary), “『岩井喜一郎と竹鶴政孝』ともに摂津酒造を退社したのち” (Japanese) — note.com
- HOMBO Official, “Komagatake” — hombo.co.jp
- Quill & Pad, “Mars Shinshu Japanese Whiskies: High-Altitude Fire And Ice” — quillandpad.com
- World Whiskies Awards, “Bronze – Mars / Komagatake Japanese Barley 8 Years Old – World Whiskies Awards 2025” — worldwhiskiesawards.com
- Forbes, “The World’s Best Whiskies: 2022 San Francisco World Spirits Competition” — forbes.com
- Skurnik Wines & Spirits, “Iwai Tradition – Sherry Cask, Mars Whisky” — skurnik.com
- Tokiwa Imports, “Mars Shinshu” — tokiwaimports.com