THE GLENALLACHIE UNVEILS PIONEERING WHISKY MATURED IN RARE MONGOLIAN VIRGIN OAK


THE GLENALLACHIE UNVEILS PIONEERING WHISKY MATURED IN RARE MONGOLIAN VIRGIN OAK
The GlenAllachie Distillery today, Thursday 10th September, introduced the fourth chapter in its celebrated Sinteis Series – a 2015 Mongolian Virgin Oak, Pedro Ximénez & Oloroso Sherry Cask Matured Single Malt Scotch Whisky.
This 10-year-old limited edition marks the first Scotch whisky matured in elusive Mongolian virgin oak to be bottled for global release, reflecting The GlenAllachie’s pioneering approach to wood mastery and its continued evolution of the Sinteis Series. This fourth edition embodies an ethos of ‘A Convergence of Three: Three Casks, Three Stories, One Exceptional Whisky.’
‘Sinteis’ (pronounced sin-teesh), meaning ‘synthesis’ in Scottish Gaelic, captures the essence of The GlenAllachie’s cask innovation, uniting the bold and expressive virgin oak with the familiar warmth of sherry casks to create distinctive, boundary-pushing expressions.
While previous expressions in the series explored a dual cask approach, Part IV was initially matured in bourbon barrels before spending time separately in Pedro Ximénez and Oloroso sherry casks. The whiskies were then combined and transferred to rare Mongolian virgin oak casks.
Mongolian virgin oak casks, crafted from Quercus Mongolica, are hard to source and unforgiving in character. Consequently, this wood type has remained largely unexplored in Scotch whisky. This oak is scarce in nature, having to be grown for over a century and naturally felled in order to be used commercially. Sourced from the forests of East Asia and noted for their tight grain structure and remarkable density, the wood reveals rich caramel, subtle sandalwood and oriental incense nuances.
Sinteis Part IV showcases this harmony with two types of sherry casks. Oloroso infuses the whisky with layers of dried fruit, dark chocolate, and nutty complexity, while Pedro Ximénez brings sweet toffee and treacle. The final whisky reveals dark chocolate, layered orchard fruits and warm pastries; a celebration of each cask’s distinct character, converging perfectly into one.
Commenting on the new release, Master Distiller Billy Walker said:
“The Sinteis series has allowed us to explore the interaction between different virgin oak and sherry casks. The series has explored dual-cask maturation in considerable depth already so for Sinteis Part IV I wanted to invite a pivoted approach that would be both a challenge and an adventure.
“We work intensively with Pedro Ximénez and Oloroso sherry casks, so moving the liquid into Mongolian virgin oak was certainly an exciting challenge. The wood’s unforgiving nature and rarity in whisky-making meant we had little precedent to work from. As a team, we trusted in our instinct and experience, and I’m exceptionally proud of the whisky we’ve created and to be able to showcase the beautiful character of Mongolian oak.”
Sinteis IV is bottled at a cask strength of 58.5%, with natural colour and without chill filtration, preserving the full character and integrity of cask maturation. Each release in the Sinteis Series is a limited-edition bottling, distinct in its own right.
The bespoke packaging features a hand-drawn motif inspired by Quercus Mongolica and united by an endless knot, based on the geometric ornamentation found throughout traditional East Asian art as well as the enduring relationship between wood, whisky and time. The balance between natural forms and precise geometry, accented with ornate gold foil, reflects the intricate balance of nature and craft found within this expression.
The GlenAllachie Sinteis Part IV, 2015 Mongolian Virgin Oak, Pedro Ximénez & Oloroso Sherry Cask Matured, is available with a UK RRP of £75.99 from The GlenAllachie Distillery and online at www.theglenallachie.com from September 10. It will become available globally in the coming weeks.
The Sinteis Series – Sinteis Part IV, 2015 Mongolian Virgin Oak, Pedro Ximénez & Oloroso Sherry Cask Matured
- 10 years old single malt whisky
- Limited edition release
- Bottled at cask strength 58.5%
- Natural colour and non-chill filtered
Tasting Notes
Colour: Burnished Chestnut.
Nose: Baked pastries, and butterscotch, followed by brandied orchard fruits, cocoa and treacle tart, with cinnamon and crystallised ginger.
Taste: Candied hazelnuts, baking spices and plum syrup, followed by spiced baked orange, vanilla ice cream and mocha, with mānuka honey and fig jam.
About The GlenAllachie
Since re-emerging under independent ownership in 2017, The GlenAllachie has made bold, strategic choices rooted in flavour integrity over volume. By fine-tuning fermentation practices, streamlining production, and investing heavily in cask management, the distillery has cultivated a house style renowned for depth, complexity, and individuality.
Beyond the stillhouse, The GlenAllachie’s influence continues to grow, with high-profile and innovative releases such as The Sinteis Series, and age-stated limited editions earning global acclaim. The distillery’s commitment to transparency – bottling at natural colour, non-chill filtered, and often at cask strength – underscores its dedication to the discerning whisky drinker.
Prioritising the production of quality spirit, the GlenAllachie Distillery chose to reduce its production capacity from four million to around one million litres of alcohol and increase its fermentation period to 160 hours – almost three times the industry standard – for an ester-rich, fruity spirit.
The GlenAllachie also maintains a strong focus on sustainability and provenance, with local sourcing and traditional methods guiding much of its ethos. Supported by the Scottish Industrial Energy Transformation Fund (SIETF), a state-of-the-art Mechanical Vapour Recompression (MVR) system was installed at the distillery to capture and recycle waste heat from distillation, using it to reheat the stills. It is a distillery that not only honours Scotch whisky heritage but actively shapes its future.
About Billy Walker
With a career spanning over 50 years, Billy Walker is a legendary figure in the Scotch whisky industry, renowned for his transformative leadership of distilleries like Benriach, Glendronach, and Glenglassaugh. Celebrated for his innovative use of casks and unwavering commitment to quality, he is now the owner and Master Blender at The GlenAllachie.
Under his stewardship, the company has achieved widespread acclaim. Among its many accolades, the GlenAllachie 12-year-old was named World’s Best Single Malt at the 2025 World Whiskies Awards.
It’s from this incredible record of success that Billy has cemented his reputation as one of the most prominent whisky figures of his generation.







































