There's more to peat than meets the eye...
Peat: for many, it’s a love it or leave it affair. Tasting notes like ‘Burning Hospitals’, ‘boat engines’, ‘antiseptic’, ‘ashes after a bonfire’, ‘tar pits’, ‘charred bacon’ and what not may not seem appealing at first glance, for many peat aficionados it sounds like heaven in a glass.
When we talk about peated whisky, immediately and almost synonymously, Islay springs to mind. However, peatfired kilns were once the most common way to start any whisky production anywhere in Scotland. Simply because as a fuel source it was readily available, whereas coal or wood weren’t. Roughly 12% of Scotland’s surface consists of peatlands, so for the peatheads out there: there is absolutely no danger of running out of the stuff in time to come. Once the most common of fuel sources for both distilling and domestic use, during the 20th century – particularly after WWII, more and more distilleries stopped using it, preferring coal and wood to create a lighter style whisky to cater to the fashion. Peated whisky didn’t disappear entirely of course, but apart from Islay, it became a rarity more than anything. On Islay, neither coal nor wood were abundantly available, meaning that, as resources go, they were pretty expensive. Peat however, was and is pretty much all over the place, so they simply stuck to their old ways.
By the 1960’s and 1970’s, whisky was booming once again, thriving on the success of blended scotch. While peated single malt as a category was pretty unheard of, the big companies like DLC, Hiram Walker and William Grant relied on the Islay distilleries to provide peated malt for their blends. And in the rare occasion of there being a peated whisky shortage, they simply built a distillery elsewhere that produced (heavily) peated single malt, as was the case with Brora/Clynelish.
Of course all of that changed abruptly in the 1980’s and 1990’ies with the whiskylog. Decreasing demand meant that many distilleries throughout Scotland had to close their doors, a significant amount of them permanently as it turned out, and now came a time where you simply couldn’t give peated malt away. Port Ellen closed, as did Bruichladdich and Ardbeg, twice even, over the course of just 15 years, while Bunnahabhain remained silent between 1982 and 1984.
But, as Bob Dylan already knew, the times they are a changing. Today, Islay single malt whisky is among the most sought after in the world, leading to heavily inflated prices, both on MSRP as on secondary markets. Islay whisky in particular is a prime example of today’s whisky landscape. Despite there now being more whisky produced than ever (at the turn of the millennium, there were 5 operating distilleries on Islay – 6 if you want to include Ardbeg that had just restarted production again, today there are 9, with 2 more in the making, one of which Port Ellen being brought back to life) , and the quality being second to none, production simply doesn’t seem to be able to hold up with current demand.
The demand for peated whiskies didn’t go unnoticed elsewhere in Scotland (and abroad, for that matter), and quite a few other distilleries over the years have started releasing whiskies that are, to one extent or the other, peated. Some, like Benromach, Springbank or more recently Torabhaig, have pretty much built their core range around it. Others, like Balvenie, are content with releasing a yearly batch of peated whisky.
It’s fair to say, peated whisky has been reinstated and –despite making up only some 10% of all scotch single malt whisky - counts for a vital part of today’s global success story of Scotch. And while Laphroaig, Lagavulin, Ardbeg et al have established somewhat of a cult following some very dedicated fans amongst those appreciating the sooty, smoky, medicinal characters from these distilleries, the coming weeks I’ll try to expand the horizon, away from the usual suspects and see what else is out there. But first things first: what is peat, and how does it work when it comes to whisky?
We all know, more or less, how peated whisky works. Peat is, simply put, what you get when vegetation (plants, moss or other organic matter) starts to decay. Those bits and pieces that don’t fully decay (because they ‘re not fully submitted to anaerobic and acidic conditions), only decompose partially and become, over the course of time, peat. I already mentioned that some 12% of Scotland’s surface consists of peat, but globally, some 1.4 million square miles (3.4 million square kilometres) is made of peatland ecosystems. Peat is also absolutely vital for this planet not turning into one hot dustbowl, as it’s the world’s most efficient carbon sink - land clearances of peat bogs for agricultural purposes and burning peat on a massive scale are indeed a threat to be taken seriously. So hooray for peat! The small issue here is of course that it takes time for peatlands to grow, a whole lot of precious time (I already quoted Bob Dylan, so why not throw in George Harrison as well?). Just 2 cm of peat soil (3/4 of an inch) takes about a century to grow. Take into account the average peatbog is some 1.5 to 2.5 meter deep (5-7.5 feet), and we’re looking at a loooooong time. The youngest peatbogs out there are roughly 10 – 12,000 years old.
OK, back to whisky. Distilleries releasing peated whisky tend to use words like ‘lightly peated’ or ‘heavily peated’, often mentioning the ppm level, which stands for phenolic parts per million, as you probably know. So as a general rule, the higher the ppm, the more heavily peated the whisky. It’s basically how the entire marketing campaign of Octomore works.
Except, it isn’t that simple.
While ppm is an indication about what you might expect, it’s not the be all and end all of things, pretty much in the same way that while an age statement is telling you something about your whisky, it shouldn’t be confused with it being an indication of quality.
This isn’t by any means meant as a criticism towards distilleries putting that ppm information on their label, as going into full detail about the whole business of peat would soon turn into a masterclass about organic chemistry, and a bottle label only has so much room for words and graphics. Quite the contrary, as many other enthusiasts, I embrace any information and transparency provided by producers. We just need to bear in mind that it’s also, not just information being disclosed but also a clever bit of marketing. Having said that, we should also and always bear in mind that the ppm mentioned on those labels is a measurement of the phenols before the actual process of distilling takes place. It’s safe to assume that a lot (if not all) of the chemical processes involved in making whisky, from kilning (do you let it smoulder and smoke rather than burn it), to mashing, fermentation, distillation and finally maturation, will impact how much ppm actually end up in your bottle. It was even deemed true for a long time that the peatiness of the watersource used in making whisky had an impact on the flavour, but let’s not go there as that’s proven to be myth more than actual truth.
What I’ll try to do, is break it down a bit and try and find out how peat and whisky work together. I’m by no means an expert on peat, nor do I know an awful lot about organic chemistry, so all of the following information I got from books, the internet and presentations from people in the industry. Think of this as a mere introduction, and I’ll put the sources at the bottom so you can click through and get your proper anorak on if you want to. So I hope I don’t bugger up too much and please forgive me if I’m cutting a few corners left and right or even get lost in the woods, as I’m just an amateur trying to make sense of things.
Let’s start with the basics. What defines the flavour/taste/character of peat, is first and foremost determined by the vegetation it’s made out of. To name but two obvious examples, Islay peat is different from Orkney peat, simply because the ‘basic ingredient’ is quite different. There’s the heathery, slightly sweet and floral peat used by Highland Park and then there’s the grassy (sedges) and mossy vegetation, often carrying seaweed and oceanic minerals in it, that contributes hugely to the peatbogs of Islay. Different vegetation = different peat = different character of peat. Pretty straightforward so far.
Then there’s phenols, and this is where things get a bit more complex. As said, most distilleries make do by mentioning the ppm of the phenols to indicate how heavily peated a whisky is. But there’s more to it.
Phenols consist of multiple compounds, carrying different aromatic qualities. The most elementary and obvious one being phenol (duh), but there’s also things like Cresol and Guaiacol, both of which in turn can be divided up even more. The classic medicinal, antiseptic, musty notes are said to come mostly from phenols and cresols, while the smoky, nutty, bacon, woody ad spice flavours are attributed to guaiacols (for a complete overview: please check the article by Dave Broom). Of course the proportions of these components changes as you –literally- dig deeper and go from younger (wet) to older (dry) peat and it’s the proportions in which these individual phenols end up in the oven, kilning the barley, that will heavily impact the end result. Where ‘in the old days’ both older peat (the dark, more bricklike part giving off heat like burning coal would) and younger, top layer, ‘wet’ peat (giving off smoke carrying a shit load of phenols) were used, today it tends to be only the top layer that’s being used, as there are other materials available to provide the necessary heath. In order for the peat to actually impact the barley, you need first of all to have lingering and smoking rather than actual burning peat, and secondly, the barley must still be moist. If the barley is either too wet or too dry, the smoke will simply pass across without impacting the flavour of the malt.
It doesn’t end there (please, bear with me, nearly there). The barley variety plays a part (yield, and also how receptive it is to the peat smoke, although the impact here might be subtle), and – more importantly - also the whole distillation process. Shape and size of the stills and the pace of distilling hugely impact all flavours in whisky, so it’s no different with a peated wash. For example, pot stills collecting the spirit from peated barley at roughly 70% ABV would result in there being more outspoken medicinal notes, but as phenols only tend to come up near the end of a distillation run (and thus, depending if you go into higher or lower collecting strength), you’ll be picking up either more or less of the other characteristics like smoke and spices, as the lower phenol levels allow for more of these other characteristics to come through. So playing with your cutpoints will allow you to influence the character of your new make spirit.
The final stage, the maturation process, also plays an important part in how peaty your whisky will end up. The basic rule here, as with all whisky, is that the longer the spirit rests in the cask, the more the wood influence becomes obvious and the initial character of the new make ‘diminishes’ – be it floral, sweet, vegetal or peaty. Obviously there’s variables within this variable, depending on how active the cask is. A first fill sherry but is likely to make its mark faster and more dramatically than a 3d fill bourbon hogshead. As on the subject of chill filtering, it doesn’t seem to impact peat flavour in whisky. To my knowledge, chill filtering does not strip out ppm (or else Laphroaig would be pretty buggered), so I’ll just leave it at that.
The science behind the impact of peat on whisky still has a lot of ground to cover, so with a bit of luck what we’ll see happening in time to come won’t be unlike the knowledge we now have when it comes to wood and casks, where a well-planned cask and maturation policy has delivered some tremendous results in recent years. That too is a relatively new phenomenon, and it’ll be exciting to see how much more there is to learn when it comes to peated whisky.
In any case there’s more to peat than meets the eye, as it is with many things whisky. Just like casks, stills, fermentation, warehousing, barley: each and every aspect of whisky and how it is being made allows you to get your anorak on and start nerding out. Don’t you just love it?
What initially was meant to be a brief introduction to a first review on peated whisky not from Islay, turned out into a full-fledged, + 2000 words blogpost, so I’ll leave it at that for today and I’ll start with the reviews from next week’s post on. Slainte, and lang may yer kiln reek!
Sources:
Michael Jackson. Whisky – The definitive world guide (Published by Dorling Kindersley Ltd in 2005)
Certified Originals tasting with Michael Henry from Loch Lomond in November 2021 (private session, yet free for all CO’s, so you should totally join): https://newdramdrinker.weebly.com/certified-originals.html
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