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Ireland’s first chimney-free, zero emissions distillery established in Co Galway mill

Couple employs innovative heat pump technology to replace traditional methods involved in distillation

A Dublin couple who moved from Asia to Ahascragh, a small village in east Co Galway, have built Ireland’s first chimney-free, zero emission distillery.

Ahascragh Mill dates back to the early 1800s and until the 1950s processed grain into flour.

Gareth and Michelle McAllister first saw the now-derelict mill advertised for sale while they were based in Hong Kong but did not act until the following year, when they were in Galway for a meeting.

Having lived and worked in countries across Europe, the US and Asia, the couple returned to Ireland in 2020. Constructing the eco-friendly distillery became their lockdown project.


Gareth had worked in Asia as a chemical engineer and said that his background has always been around sustainability and the environment — hence why he and his wife chose to go the zero-emission route.

“The distillation process of making spirits, or making whiskey, is very energy intense, and there’s something like three to four kilos of carbon dioxide equivalent emitted per bottle,” he said.

“We were never going to put something in there that would follow tradition in the industry, but the technology we’re using, I’ve used elsewhere around the world, and I know it works.”

The distillery uses a very high temperature heat pump system. “I’ve seen it work elsewhere — it just hasn’t been used in this industry, so that’s what became the challenge, applying it from a process industry to a distilling industry,” Gareth explained.

Global innovation

The Dublin native also added that being zero emissions is a differentiator for the company in the marketplace: “We’ll give the consumer a choice to buy a product that hasn’t damaged the environment in its production.

“Even the packaging that we use in one of our brands is completely recyclable,” he said, adding that it has proven to be a good business model plus “the right thing to do” in terms of sustainability.

The couple say that they had always planned on repurposing an old building, and when they saw the old mill, which was originally powered by hydropower before it became derelict some 70 years ago, they decided it was a perfect fit.

Renovating the old mill is “probably twice as expensive” as building a distillery from scratch, the chemical engineer added, because of the skilled labour required alongside materials that are controlled by the conservation officer.

“It’s a shame, there’s so many derelict old buildings like this in the country and there should be an incentive for people to do something like this,” Gareth added.

The couple also want others to observe the work they are doing to build a chimney free distillery. “We’re not secretive about what we’re doing here. We’re publishing it, people can copy it, because I think it is better for all of us if the whole industry switched to this kind of energy system,” said Gareth.

“There’s been actually four sets of engineering eyes on this process. Not one of them have come back and said, ‘oh, I’ve seen this before’. They have all come back and said, ‘this is brand new, it’s going to work because we’ve done our calculations, it’s innovative, but it’s newness makes them a bit scary’.”

David Connolly, chief technology officer of Astatine, renewable energy and decarbonisation specialists based in Ireland, described what the McAllisters are doing in the distillery as a “seminal moment”.

“On a global innovation, to my knowledge, they are going to become the first distillery in the world that doesn’t have a chimney, so what they are doing has never been done globally before,” Mr Connolly said.

“People have always had to burn something in a distillery to create whiskey, and as a result there has always been some kind of emission coming out of the facility, whereas this facility will have no chimney, it’ll have no emissions.”

Mr Connolly added that the project is setting a “new benchmark as to what can be done at a distillery”, but also that Astatine have “a long list of clients that are keenly watching this project in Ahascragh, not because it’s the distillery, but just purely because of the type of energy solution it is, and how applicable it will be in trying to decarbonise their own sectors as a solution”.

In 2021, The Ahascragh Distillery launched its first products including Clan Colla Irish Whiskey, UAIS Irish Whiskey and Xin Gin.