Originally Posted by Martin
Is there a way to measure it, kind of like measuring the strength in different chillies or is it subjective?
The conventional way to 'scientifically' gauge a whisky's 'smokiness' is to assess the phenolic content (usually measured in parts per million, or 'ppm'). This value normally diminishes over the course of distillation and maturation, yet can still maintain a palpable presence in the final bottled product. Unfortunately, such an analysis oversimplifies and therefore obscures more complex factors lying behind the 'smoke'.
Why? Simply because the exposure of barley to smoke fumes (whether from burning peat, coal or a combination of the two) during the malting process varies not only owing to differences in the 'fuels' (peat moss can cover a wide range of constituents depending on locality and depth of cut), but also owing to length of exposure. Furthermore, the water supplies of many distilleries are renowned for containing traces of peat as well as other vegetative and mineral substances, all of which can contribute brackish elements to the flavour spectrum of the final whisky. Think Talisker, for one.
Finally, there's the question of exactly how those 'smoky' nuances meld with the innate characteristics of the spirit itself. This is why some whiskies, even though they possess lower levels of phenols, may actually seem 'smokier' than others with higher levels of phenols.