Ppm - level
The amount of peat or 'peat' used during the manufacturing process defines how smoky the whisky will ultimately be. The exact amount is given in the unit ppm (phenol - parts per million). If the ppm level of a whisky is indicated on the bottle, you can get an idea of how much smoke you can expect. The ppm level can drop over time in bottles of whisky that have been left half-full or below for too long. It's not just the ppm level that suffers in a bottle with too much oxygen, all the characteristics and strengths of the whisky fade over time if there is too much oxygen in the bottle. Therefore, if you want an open bottle of whisky to retain its character for longer, it's best to pour your batches into smaller containers.
Reading the ppm level
A very mildly smoked whisky such as Bunnahabhain 12 can be measured down to around 2 ppm. Here, the smoke only appears as a small hint in the background and in most cases will not bother anyone who otherwise dislikes smoked whisky.
A lightly smoked whisky, such as Highland Park 12 or Talisker 10, measures around 20 ppm. Here, the smoke is much more prominent and gives a distinct but not overwhelming note of smoke. This is a great place to start if you like the taste of peat smoke without it dominating the taste experience.
A heavily smoky whisky, as seen in the Islay region, is measured at anything above 30+ ppm. For example, the Islay classic Ardbeg 10 is around 55 ppm. Here, the smoke is dominant, powerful and takes up a lot of space in the overall impression of the whisky.
It can be a sport to see how heavily smoky a whisky can be. Bruichladdich holds the number 1 spot as the distillery that produces whisky with the highest ppm level with their excellent Octomore series. In this range there are whiskies that have been smoked to over 300 ppm. This type of whisky requires patience as well as a thick wallet, but also returns the favor with great sensory experiences.
Alternative smoke
Although peat-smoked whisky is by far the most recognized and widespread form of smoked whisky, there are distilleries with a different approach.
To find a good example of this, we need look no further than Give, where we find the Fary Lochan distillery. Here, nettles are used to smoke the malt, creating an exciting vegetal form of smoke in the whisky.
Moving on to Iceland, we find the Eimverk distillery. They produce Flóki whisky using nothing less than sheep excrement to smoke the malt. This may not sound very welcoming to many, but it's actually an old Icelandic method of smoking food and has also been used as a heat source. The results speak for themselves and Flóki whisky is enjoyed by many whisky lovers around the world.
The last example I'll touch on is the Americans, more specifically the Balcones distillery in Texas. Balcones has made a smoked corn whiskey called 'Brimstone'. Here, a new method is used where the finished whiskey is smoked with local "sun-roasted scrub oak" as they describe it. This method has brought a lot of publicity and it is very possible that it will be used more often by other American distilleries in the future.
Commonplace
Peated whisky or smoked whisky will never go mainstream and there's nothing wrong with that. There is much more to the whisky world than smoked whisky and there should be something for everyone. For myself, I was not convinced at all when I first encountered smoked whisky. But after repeated encounters with smoked whisky, I really started to like it. Today, several of my favorite distilleries are located in the Islay region.
