Tsunuki distillery: Mars whisky’s return to its birthplace

Tsunuki (津貫) is where Honbo Shuzo, the company behind Mars Whisky, began making alcohol in the first place. Long before the firm ever distilled a drop of whisky, it was pressing and processing local farm produce in this mountain basin at the southwestern tip of Kagoshima’s Satsuma Peninsula. That history matters more than usual here: when Honbo Shuzo built a second malt distillery in 2016, it did not pick a scenic new location. It rebuilt on its own founding ground, on a site the company had held since the Meiji era.

A dream deferred: from shochu licence to whisky, 1949 to 2016

Honbo Shuzo’s roots in Tsunuki go back to 1872, when the company started as a local produce and alcohol business in what is now Minamisatsuma. By 1909 it had moved into shochu production, and shochu remained the core of the business for decades. In 1949, the company obtained a whisky manufacturing licence, a fact the brand itself now frames as the start of a long-held ambition rather than an immediate product launch.

According to Honbo Shuzo’s own account of the brand, the company held onto a wish for decades: to one day make “genuine whisky that draws on Japan’s climate and terroir” (「いつか日本の風土を生かした本物のウイスキーを造りたい」). That line, repeated in the company’s product materials for Single Malt Tsunuki, is worth taking at face value: it explains why the licence sat for so long before the company acted on it at scale, and why Tsunuki was worth waiting for rather than a shortcut to a second production site.

Honbo Shuzo’s first malt whisky distillery, Mars Shinshu (see our Mars Shinshu distillery guide), opened in Nagano in 1985, was mothballed in 1992 during the industry downturn, and resumed distilling in 2011 as Japanese whisky demand recovered. Tsunuki came next, in 2016, and the company placed it deliberately on the grounds where Honbo Shuzo itself began. The distillery sits next to Hōjō (寶常), the 1933 residence of the company’s second president, since renovated into a cafe and bar for visitors. A 26-metre shochu distillation tower from the company’s earlier era still stands on the property, kept rather than demolished. Tsunuki is not a green-field whisky project; it is a shochu maker’s home ground converted, deliberately, to a second calling.

Why the grist ratio at Tsunuki runs heavier than at Shinshu

Honbo Shuzo did not build Tsunuki to duplicate Mars Shinshu. It built it to be different, and that intention shows up in a concrete production choice rather than a marketing line. Reporting on the two distilleries has noted that Tsunuki works with a different malt grist ratio to Shinshu (roughly 2:6:2 versus 2:7:1 in the milling split), a change aimed at producing a heavier-bodied spirit at Tsunuki than the house makes in Nagano.

That decision only makes sense alongside the site itself. Mars Shinshu sits at 798 metres in the foothills of Mount Komagatake, high enough that atmospheric pressure alone lowers the boiling point in the stills, a natural form of reduced-pressure distillation that tends toward a lighter spirit. Tsunuki sits at roughly 60 metres above sea level in a warm southern basin. Rather than fight that contrast, Honbo Shuzo built its process to lean into it: a mountain distillery built for delicacy, and a southern one deliberately built for weight. The two sites were designed from the outset to be opposites, not siblings.

A basin climate that swings hot and cold, and what that does to the cask

Tsunuki’s location is a basin ringed by the Kuratayama mountains, and basins trap temperature extremes. Summers here run hot; winters, despite the southern latitude, turn unusually cold for the region. Honbo Shuzo’s own description of the site is blunt about this: it is one of the more thermally punishing spots in southern Satsuma, not a mild coastal setting.

That swing is the point. Tanaka Norifumi, who oversees the cafe and bar at the distillery, has described the effect on the cask directly: the repeated expansion and contraction of the wood as temperatures swing pulls more of the barrel’s own character into the spirit, producing what he calls a robust, distinctly Kagoshima-style character in the whisky. It is a plainer explanation than most distilleries offer for why their location matters, and it ties a specific climate condition to a specific effect on the liquid rather than leaving the connection to atmosphere and photography.

The distillery also draws its process water from the Kuratayama mountain system, water Honbo Shuzo credits alongside the climate for the character of Single Malt Tsunuki. Between the water source, the grist ratio, and the basin’s temperature swings, Tsunuki’s profile is built from three separate, stated decisions rather than one.

Two distilleries, three ageing sites: Honbo Shuzo’s climate strategy

Tsunuki is only half of a wider plan. Honbo Shuzo now runs two malt distilleries, Mars Shinshu in Nagano and Mars Tsunuki in Kagoshima, and in 2016 it added a third element: the Yakushima Ageing Cellar, a warehouse on the World Heritage-listed island south of Kyushu that holds no stills at all. Yakushima’s climate is wet and humid in a way neither Nagano’s mountains nor Tsunuki’s basin are, and the company uses it specifically to mature spirit from both distilleries under a third set of conditions.

The company’s own framing of this is a “two distilleries, three ageing cellars” structure, built explicitly to give it a wider range of maturation environments than a single-site distillery could ever offer, without having to change where the spirit is actually made. It is a strategy that only works because the three locations are genuinely different from each other: a cool 798-metre mountain site, a hot-and-cold southern basin, and a humid subtropical island. Reduce any one of those differences and the logic of running three sites collapses.

For readers used to single-site Scotch distilleries, this is a distinctly Japanese solution to a distinctly Japanese problem: a whisky industry rebuilding itself with far fewer decades of aged stock in the ground than Scotland has, using geography itself as a tool to widen the flavour range available from what stock exists.

What Single Malt Tsunuki says about itself

Honbo Shuzo bottles the distillery’s output as Single Malt Tsunuki, released in yearly editions rather than as a single fixed product. The brand’s own product notes describe a whisky built mainly from bourbon barrel and sherry cask maturation, vatted for what the company calls a deep, rounded sweetness alongside a lively fruit character, and attribute that profile directly to the basin’s climate and the Kuratayama water rather than to any single cask type.

What is notable in the brand’s own language is how little it leans on scenery. Where some Japanese whisky marketing reaches for cherry blossoms or Mount Fuji, Honbo Shuzo’s account of Tsunuki stays close to the specific: a licence held since 1949, a founding site reused rather than replaced, a named member of staff explaining a named mechanism (barrel expansion and contraction) for why the whisky tastes the way it does. That restraint is itself a kind of statement about what the company thinks makes the bottle worth choosing: process and place, stated plainly, rather than atmosphere.

For a drinker outside Japan, that is the real reason Tsunuki is worth seeking out rather than treating as a curiosity. The bottle is not the product of a company chasing a whisky trend; it is the product of a shochu maker that held a whisky licence for decades before using it at this site, then built its second distillery to deliberately contrast with its first. Every stated choice, from the grist ratio to the choice of ageing sites, traces back to that original 1949 decision to wait rather than rush. Knowing that changes what is in the glass: not a generic “Japanese whisky” entry, but the specific, documented outcome of one company’s long view of its own history.

Visiting Tsunuki, and how it compares with Mars Shinshu

The distillery is open for tours that take in the pot stills, the stone-walled cask warehouse converted from the site’s shochu-era storage, and Hōjō, the 1933 former residence turned cafe and bar, where visitors can taste on site. Because Tsunuki and Mars Shinshu are run by the same company but built around opposite conditions, they are worth comparing directly rather than reading about in isolation.

Readers curious how this fits into the wider recovery of Japanese whisky, including the industry conditions that shut Mars Shinshu down in 1992 and reopened it in 2011, may also want our overview of what counts as Japanese whisky under the labelling standard, and how the category compares with Scotch in our guide to Japanese whisky vs Scotch. Kagoshima itself now has more than one whisky maker worth knowing; see our guide to Kanosuke distillery, on the other side of the prefecture, for a second take on how a Kyushu location shapes a house style.

Sources

• Honbo Shuzo, official Mars Whisky Tsunuki distillery page (Japanese)
• WHISKY Magazine Japan, “マルス津貫蒸溜所の輝ける未来” (Japanese)
• Serai.jp, “焼酎蔵の蒸留所を訪ねる：マルス津貫蒸溜所（鹿児島・南さつま）” (Japanese)
• Honbo Shuzo, Single Malt Tsunuki product notes, shop-hombo.jp (Japanese)
• note.com, “『マルスウイスキー/本坊酒造』の「2蒸溜所・3熟成庫」体制！” (Japanese)