Peated whiskey has been described as Marmite by Iain Banks in his book “Raw Spirit”, as in you either love it or hate it. From most general literature and online debate, that would seem to hold true. It’s also often given as one of the main differences between Irish whiskey and Scotch, smokiness vs. smoothness, heavy vs. light. But what is the difference between peated and unpeated whisk(e)y and is it really as definitive as it’s made out to be?

First off, we should dispel some myths: not all Scotch is peated and not all Irish whiskey is unpeated. They are however generalizations which hold true more often than not, and in the case of Irish whiskey the vast majority is indeed unpeated. The exceptions to the rule are Connemara (which is also only double distilled, so breaking another “rule” of Irish whiskey) as well as some private bottlings such as Inishowen and Michael Collins. Over in Scotland the whiskies are often epitomized by the heavily smoky Islay malts, but Glengoyne, for example, uses no peat at all in its kilning process.

It is in the malting process that peating plays its role. Germinating barley starts to release the proteins and sugars necessary for growth, which is then halted through drying. In the case of peated malts, the moist and sprouting barley is laid out along a drying floor which has a fire underneath, powered by peat. This smoke rises through tiny holes in the floor and circulates in the room, creating temperatures of up to 70C. The smoke from the peat imparts phenols to the barley grain, which is how the smokiness of whiskies is measured. For example, a traditional Islay malt will be between around 30 – 60 ppm, with some, like Octomore, being over 100, which would taste like the smoke from a full cigar condensed in a glass… which is fantastic if that’s exactly what you’re looking for!

Unpeated malts however, most commonly used in whiskey making on the island of Ireland, are dried in kilns and thus never come into contact with smoke. Not only that, but the unique Single Pot Still method used in some of the most loved Irish whiskeys involves the usage of both malted and unmalted barley, in about a 40:60 ratio. This reduces even further the possibility for smokiness (malted barley produces a very slight smoky flavour after malting all of its own accord). Thus the vast majority of Irish whiskey has a much smoother and more delicate palate compared to its Scotch cousins, to generalize again obviously.

When it comes to flavour, and what it means for individual drinkers, there lies the beauty for the whisk(e)y lover. Depending on one’s mood, the weather, the setting or whether that person you like has texted you back in the past three days or not, there’s a whisk(e)y and a flavour out there for every occasion. My personal preference is for the smoothness of Irish whiskey, arguing as I do that it allows for greater appreciation of subtler notes, without being overpowered by a feeling you’re trapped in a burning haybarn. Variety is the spice of life however and enjoying a dram with a passionate lover of Ardbeg or Caol Ila has its own rewards.

As the French would say (surprisingly huge whiskey fans) vive la différence!