A tippler might not know it from the pretty advertisements, which hype the mountain streams and woolly highlands, but making Scotch whisky can be a dirty business — an energy-intensive, carbon-spewing, peat-burning industry, mostly owned by multinational conglomerates that ship their $50-plus bottles to swells around the world.

On the picture-perfect western isles of Scotland famous for their whiskies — Islay, Skye, Jura, Arran — the whitewashed distilleries are often the largest sources of greenhouse gas emissions in their bucolic regions, ahead of the diesel ferries and pastures of belching sheep.

But something head-turning is happening.

The owners of the 140 distilleries in Scotland have pledged, voluntarily, to transform the industry and make their operations “net-zero” in carbon emissions by 2040, a decade earlier than Britain as a whole and five years earlier than Scotland has promised.

The Scotch Whisky Association wants consumers to imagine a future when the old-time distilleries turn away from fossil fuels and toward energy generated by wind and wood chips, by ocean tides and 21st-century green hydrogen.

They see a day when whisky makers will more wisely husband Scotland’s water and better recycle their waste, and deploy the dregs — the byproducts like draff and pot ale — into a virtuous “circular economy” of fertilizer, animal feed and biofuel.

Soon, they hope, those road-hogging buses that trundle tourists on narrow roads around lochs on whisky-tasting tours will run on batteries topped up at the 30,000 new charging stations Scotland has promised by 2030.

Whether the whisky business will be able to pull this off, and do it so quickly, is uncertain. Many polluting industries — shipping, steel, aviation, cement — are similarly vowing rapid change, based on technologies that are not yet available on a commercial scale. It can be difficult to separate serious commitment from campaign slogans.

But Scotland’s distillers have some things going for them. They’ve got deep pockets in a rich country with big green ambitions. They can benefit from Scotland’s shift to renewables, and they have the financial resources to give their net-zero experiments a go. Scotch whisky is the United Kingdom’s single largest food and drink export, with annual sales valued at $7.5 billion in 2022.

Scottish distilleries also take a long view. They are part of a tradition that goes back centuries, and they think in decades, producing spirits that often spend 12 years or more maturing in casks. They can see clearly that there is only one direction to go.

Many promises, some progress

It helps that international energy producers have descended on Scotland to make eye-popping, billion-dollar investments, which envision the coastal waters covered by vast wind farms pumping electricity to shore, with some of that electricity diverted to make commercial green hydrogen, one of the holy grails for a net-zero world.

Those wind farms will be located just offshore from the whisky isles.

Piggybacking on Scotland’s green transition, the whisky sector here has reduced its carbon emissions by more than half since 2009, as it has gone from consuming just 2 percent renewable energy to 39 percent renewable in 2022.

The industry is making its own investments, too — with mixed results.

The Ardgowan Distillery, partnering with a university and an engineering company, has pledged to be “carbon negative” in its operations by next year, by developing technology to capture all the CO2 in its fermentation process and transforming it into green bio-methane.

That would be remarkable. Today most distilleries just vent their carbon dioxide directly into the atmosphere, as there is no market for it.

At the Glengoyne Distillery, visitors can tour its settling ponds, filled with reeds, designed to clean the wastewater. The maker’s solid waste is now harvested, too, as a biofuel to power 354 nearby homes. They’ve adopted a downstream wetland.

But the distillery is still run on fossil fuels — and the treated wastewater isn’t drinkable. It just meets minimum standards to put into the bogs.

The Bruichladdich distillery made news when it pledged to go net-zero even sooner than 2030. But the company’s chief executive, Douglas Taylor, told The Washington Post, this is much harder than he imagined.

“We’re a drinks company. We’re not an energy company,” Taylor said. “We don’t own a wind turbine or tidal machine.”

He said he wants his company playing its part in a sustainable, diverse, rural ecosystem. His distillery is the largest employer on Islay, with 117 workers. Taylor buys most of his barley locally, which reduces his carbon footprint.

But in an early bid to reduce carbon emissions, the distillery tried an anaerobic digestion system to produce fuel. It failed.

The distiller switched from using heavy oil to medium oil to a commercial heating oil. A little cleaner? Yes. But a long way from net-zero.

Taylor said they’ve wanted to install hydrogen-ready boilers, but there is no hydrogen available yet on the island.

ScottishPower has begun to build the Cromarty Hydrogen Project, north of Inverness, which will use offshore wind to make green hydrogen on shore, which will be available to a hub of businesses, including the whisky maker Glenmorangie, in an industrial area. But this is far away from Taylor’s stills.

He is exploring installing his own electrolyzer to make the hydrogen and his own tanks to store it. But he doesn’t have the permits, engineering or funding yet.

“I can’t stress how complex this all is,” he said.

Wood chipper whisky

The irreducible fact, said Annabel Thomas, founder of Nc’nean distillery, is that some kind of fuel has to boil the mash and distill the alcohol. “You can’t get rid of the boiler — like you can’t get rid of the jet engine on an airplane,” said Thomas, who runs a boutique operation on the Morvern peninsula in the western Highlands, set on her family’s gorgeous estate, with stunning views of the white caps out on the loch.

In the old days, the energy to heat the kettles came from coal. Today, it’s from natural gas or fuel oil — the oil typically transported by diesel tankers plying the seas and then by diesel trucks moving along narrow farm roads.

Thomas said she has thought a lot about the future — the future of the planet and her future sales. High-end whisky is a luxury, she knows, an indulgence. “And if the industry doesn’t change, we will lose younger generations,” she said.

Her family had planted a commercial tree plantation on the property 40 years ago, and she thought why not? “It becomes very simple,” she said. “Harvest the trees, put them through the wood chipper, and feed them to the boilers, replant the trees.”

The distillery benefited from being new — launching in 2017, with the first bottles filled in 2020. They had to refurbish old barns, but they bought new boilers and didn’t have to retrofit century-old systems, as many distilleries will.

Amy Stammers is head of sustainability at Nc’nean — a job title that would not have existed five years ago. She gives a tour of the distillery as her co-workers — more women than men — bustle about the kettles, measuring, sniffing, watching gauges, like Oompa Loompas at a Wonka factory that makes 40-proof candy for adults.

“The next generation of distillery will likely be hydrogen,” Stammers said. “That is one version of the future. But when we looked at it, it’s still 10 years out. It wasn’t there yet. So it made most sense for us to use biomass, with our trees. But in the future, who knows?”

The peat problem

One of the early decisions the Nc’nean distillery made was that they would not flavor their spirits by burning peat during the kilning of the malt.

Peatlands are considered a precious resource. These waterlogged, acidic, low-nutrient ecosystems are the most carbon-dense habitats on Earth.

You want to safely store carbon for a thousand years? Nothing beats peat. It’s nature’s vault.

But peat is also central to the deep traditions of many Scotch whiskies, helping to give them their smoky flavor. None of the major brands have changed their recipes.

In its defense, the whisky industry says it uses less than 1 percent of the total peat that is extracted annually in Britain.

But still. Japan’s Beam Suntory, which owns Scotch brands including Laphroaig, recently announced a $3.5 million project aimed at restoring degraded peat bogs.

The drinks conglomerate Diageo, which sells Talisker, similarly pledged to repair hundreds of acres of peat on the isle of Islay.

Whether these kinds of mitigations are sustainable is debatable. Peat bogs are disappearing, and they accumulate carbon over centuries — not a year or two. Similarly, wood chips are renewable, but it takes decades to replace a tree.

The challenge is acute enough that even Whisky Magazine — a booster — concluded, “any way you cut it, one of the most important ingredients in whisky making is a fossil fuel — and that’s not even the worst part.”