For Peat's Sake: Whisky's hunt for sustainable smoke

Peated whisky is one of Scotland's most iconic drinks, but its unique character comes from burning a resource thousands of years in the making. Darran Edmond reflects on his love of peat, and looks forward to some possible alternatives

Feature by Darran Edmond | 29 Jul 2024
  • Peat cutting

Like most whisky fanatics, I remember the dram that started it all. Not the first sip of whisky I ever tasted – which the majority of us, if we’re being honest with ourselves, didn’t enjoy – but the first dram that really blew me away. A Burns Night ceilidh: the drams were plentiful, but for a novice like me the whiskies and their names had been whirling past, unremembered, like partners in an eightsome reel. That is, until a friend thrust a quaich under my nose that stopped me in my tracks. The aroma had the medicinal sterility of bleached-white hospital corridors, but also the raw, dirty fecundity of freshly dug earth. The wet, salty funk of a seaweed-strewn beach at low tide, and the dry, acrid smoke of the last dying embers of a campfire. “What the hell is this?” I asked. “It’s peated,” he said, smiling, “not for everyone.”

Even though I had no idea what peat was, or how those flavours could have ended up in my glass, I knew it was for me. I’d later learn that peat is a surface layer of soil that consists of partially decomposed plant matter, formed in acidic wetland conditions over thousands of years, and that on many of the rugged westerly isles of Scotland – battered by strong winds from the Atlantic and so almost devoid of trees – it has historically served as the main source of fuel. When distillers in these regions dried their malted barley, the rich, aromatic peat smoke imparted a unique character to the finished product, and in a happy accident some of the most distinctively flavoured whiskies in the world were created. However, while the fires in these peat kilns may have sparked my own love of whisky, in recent years they have also ignited a heated debate in the industry over whether or not it should be used at all.

Walking through the desolate beauty of a peat bog, it’s almost impossible to imagine the significance of the processes taking place underneath your wellies as they sink and squelch into the sodden ground below. Peatlands are, simply, the most effective terrestrial carbon sinks that we have. The 20% of Scotland’s land mass they cover is capable of storing a massive 1.7 billion tonnes of CO2 – enough to offset around 140 years’ worth of the country’s greenhouse gas emissions. And burning peat, thereby releasing its stored carbon into the atmosphere, is only half the story: cutting it in the first place results in further damage to bogs by draining them, allowing their vegetation to decompose faster to the point where they become net carbon emitters. It’s estimated that over 80% of Scotland’s peatlands are already degraded in this way, while the Scotch whisky industry continues to extract 7000 tonnes of peat per year.

Photo of peatlands, with a mountain in the background.
Peatlands at Forsinard Flows Nature Reserve near Thurso. Photo: Lucentius via Unsplash

So, if peat use is unsustainable in the long term, where else could its devotees turn for their smoke fix? The brewing industry may provide a source of inspiration. While whisky has never strayed from using pale malt – dried gently at low temperatures – for production, brewers have long utilised heavily roasted malts to make darker beers such as stouts and porters. These grains are dried (in a kind of massive but slowly-rotating tumble-dryer) at higher temperatures to encourage charring and caramelisation, creating toasty, nutty, even coffee-like flavour notes. However, in order to create the kind of intensely smoky, spicy flavours associated with peat, the grains have to be charred to such an extent that many of the enzymes responsible for converting starch into sugars are destroyed, resulting in decreased yield. Only a small fraction of these dark malts can therefore be incorporated into a mash.

A new wave of Nordic distillers, less entrenched in whisky-making tradition, have drawn inspiration from their own food heritage, where woodsmoke is commonly used as a means of preserving meat. Mackmyra in Sweden have released an expression smoked with juniper; Kyrö in Finland using alder; Thy in Denmark using beechwood; and Stauning, also in Denmark, have given a nod to their Scottish forebears by combining peat with heather. While certainly more renewable than peat, which accumulates at the glacial pace of one metre every thousand years, these would inevitably create their own sustainability issues.

One Icelandic distiller has turned to a more arcane local tradition. Hangikjöt is a local delicacy of lamb, horse or mutton cold-smoked over sheep dung, traditionally served at Christmas. Eimverk distillery’s Flóki whisky is made using barley smoked in the same way, giving the resulting spirit a flavour that may be euphemistically described as 'complex', with sweet smoke and, unsurprisingly, 'farmyard' aromas. While certainly solving the challenge around sustainability, it presents a whole new one for the marketing department.

Another sustainable option is biochar, which in this context can be thought of as a kind of synthetic peat, made by heating biomass at extremely high temperatures in an inert atmosphere. Distilling actually provides an ideal biomass candidate in the form of draff – the spent grains left behind in the mashing process – which would create a desirable closed-loop system, eliminating a waste product at the same time as removing the need for a finite resource. The issue with biochar, and all of the previously mentioned examples, is that while they can impart smoky flavour, it’s just not quite the same as peat’s complex cocktail of hydrocarbons formed over millennia of decomposition.

A glass of whisky on a wooden tabletop.
Photo: Phil Cruz via Unsplash

Indeed, moving away from peat would irrevocably sever one of the few true connections Scotch whisky has to the land of its origin. The industry’s marketing may lean heavily on the concept of 'terroir' – a philosophy borrowed from the world of wine, affirming that the character of a liquid is down to the environment in which it’s made – but there’s not much science to back it up. So where does flavour really come from? Well, there’s the cask, but the vast majority of those are sourced from either the US or Spain. There are also less romantic factors: the size and shape of the still, rate of distillation and length of fermentation, for example.

But, as I learned on that long-ago Burns Night, peat absolutely does influence the flavour of the finished product and, being simply decayed plant material, is more than the product of its environment – it is the environment. So much so that not only are peat samples drawn from different regions of the country markedly different, but peat drawn from different areas or even different depths of the same bog can display markedly different flavour chemistry. So, while peat ticks the terroir box, it’s hard to see how any novel substitute could do the same.

While my friend may have been right when it comes to whisky, when left undisturbed in its natural environment, peat certainly is for everyone – it’s one of the best allies we have in the fight to halt, and even reverse, climate change. But by continually harvesting it to flavour our national drink, we’re pulling the plug on a carbon sink we can’t afford to lose. In the near future, distillers will have to figure out a way to get the smoke into our glasses, without the fire.


Darran Edmond is a distiller, and the owner of Glasgow-based microdistillery Illicit Spirits. As well as making spirits, and drinking them, he enjoys writing about them from time to time.

This article is from issue one of GNAW, our new food and drink magazine dedicated to sharing stories from across Scotland’s food scene. Pick up a free copy from venues across Scotland, and follow GNAW on Instagram @gnawmag