Where flavour comes alive
The equinox has come and gone and banks of fog roll in as a tide, delivering autumn to these shores. As winds zealously pick up and strip the first branches bare of their foliage high on the hillsides, every tree and shrub seems to blush in unison. Gold and copper, as fiery as our spirits manager’s beard, remind us of the embers from our late summer campfires. With the change in season, they now glow in the safety of a bothy’s hearth. For at night, there’s a certain chill in the air, damp and often thick with mists exuding the fragrance of fallen leaves. And leaves indeed fall as bracken turns the colour of rust. Come huddle around the fire to hear Julien Willems’s second chapter of our tale on the Society’s peated whiskies. Today, he delves into the very heart of the matter: how is peat formed? How do different types of peat affect the flavours we perceive in our drams?
This is a time to tell the tales of the earth and the Scottish cycle of life, of long-lost forests and coastal heather moors, of water, earth, and fire. Water is absolutely essential to form peat. The reason for this is self-explanatory: peat is the accumulation of partially decayed plant and organic matter in cold (for Scottish peatlands at least), acidic, and wet conditions. It is formed in wetlands, marshes, and bogs where water and the absence of oxygen mean dead plants only partially decompose, instead of turning to compost or dust. Once withered, the plants’ remains are compacted into peat in their boggy environment over thousands of years. Left alone for millions and millions of years, peat may under the right conditions turn into coal, tar or oil. But let’s not go into that unless you’re after liquid dinosaur. If that’s your fancy, try to get hold of our small-batch blended malt, Tar Pit.
Stories Of The Bogs
Picture it, though. Ice melting around a desolate tundra, the chilling wind’s howls and monumental glaciers cracking and crunching through stone the only sounds to fill the air. Then the first settlers, raising mysterious stones so heavy that glaciers could not haul them out to sea. Then the times of plenty and the times of strife, those of peace, of blood or rebirth. These ancient peatlands have witnessed it all, while the heather, sedges and moss have grown, lived and withered, taking something of those times to the earth with them.
And this is where things get interesting. Due to their different locations, history and weather conditions, peat bogs have evolved to host different plants and ecosystems. And this means that peat harvested from former, ancient forests in the Highlands will differ from coastal, moss-rich Islay peat or from Orkney’s heather-rich peatlands. As each location boasts its own particular flora, peat composition will naturally differ. These differences may seem minor, and after all peat takes thousands of years to form. So how much of the millennia-old plant’s characteristics could survive, you might ask?
Well, their spirit lives on in a way. Comparing moss, heather and tree residues in samples from different peat bogs, Dr Barry Harrison from the Scotch Whisky Research Institute explains: “The type and amount of lignin differs between these plants, and the type and quantity of phenolic compounds released during their combustion differs as well.” First, sphagnum moss, found in abundance in some peat bogs on Islay, isn’t actually made up of lignin, but of a similar compound filling in the same structural role, and its combustion produces very phenolic and medicinal smoke as a result.
Let us now consider lignin plants such as heather and trees. As you may remember from the Spicy & Dry article, burning lignin while charring casks creates products like guaiacol. The same applies here, so in theory at least, the smoke from a lignin-rich peat should be spicier and richer in various types of guaiacols: spicy, smoky tasting compounds.
But that’s not all there is to it. Even between lignin plants, the products of combustion vary. Heather-rich peat from Orkney is said to be more floral and fragrant, whereas a peat rich in bark and woody plants – as sometimes found in the Highlands – gives off an earthier smoke.
To add a layer of complexity to the matter, the types of phenolic compounds obtained by burning peat are also linked to how much plant matter has decayed. This means that the more exposure to oxygen there is, or the longer peat is left to decay, the more medicinal phenolic compounds and the less spicy, smoky guaiacols in the smoke. This suggests that for lignin plant-rich peatlands, theoretically at least, by digging deeper for your peat or cutting peat from slightly drier peatland, the aromas in the smoke should be more medicinal and less smoky or spicy. And the more water there is in a bog, the spicier, smokier the aromas.
“In reality, plants like heather grow very deep roots, reaching far into the ground to much older, sometimes ancient strata of a bog,” says SWRI’s Dr Barry Harrison. “That adds new wood where lignin had long since mostly decayed.” Nothing is ever as clear cut as theory suggests.
Drink With Reverence
Remember though, civilisations rose and fell in the ages it took to create every single brick of peat used in maltings today. And the history of their birthplace, to quote Isildur, famous king of fictional Gondor, “is now a secret that only fire can tell”.
But how much of that secret do we actually hear? And should some secrets not stay buried forever, for the world’s sake? We have spent much time peering into the mists of time today, and history, it seems, has caught up with us.
In our fast-changing world, the questions of sustainability and responsible peat use cannot be avoided, but more on that next month. For now, let us enjoy a well-deserved dram from the Society’s Peated flavour profile, and reflect on the tales its flavours tell us.
Whatever this dram may be, I hope you will join me in sipping it along with a large measure of reverence.