By Christopher Coates

Opinion: Evidence of terroir in whisky seems to exist and not exist at the same time

Let's call it Schrödinger’s terroir
A strange kind of doublethink has a grip on much of the whisky world. We celebrate single malt as the quintessential flavour of a single place and accept that distilleries have quirks of personality which make them, broadly speaking, unique. This is almost completely without controversy. And yet, the open-armed acceptance of the importance of location to distilling does not extend to the growing of whisky’s raw materials.

This is something of a uniquely whisky-flavoured paradox. In the world of Cognac, it is so accepted that the location in which grapes are grown will influence the flavour of the spirit that the concept is enshrined in the category’s governing regulations. The soils in which grapes that are allowed to become Cognac can be cultivated are so strictly controlled that the category is actually hampering its own growth. Importantly, the rules make sense: a comparison tasting of single-cru eaux de vie from the Borderies, Fins Bois and Grande Champagne appellations, for instance, will convince even the most ardent spirit-terroir sceptic that land influences flavour.

So too in the world of mezcal, spirits distilled from the same type of agave grown in different regions of Mexico miraculously taste different, even when production parameters are kept largely consistent. (Agave expert Alejandro Aispuro suggests trying spirit made from Agave angustifolia grown in different regions, or comparing Agave salmiana spirits from San Luis Potosi to those from Oaxaca or Durango.)

In spite of the overwhelming acceptance of the role of growing location or, to use the French parlance, terroir, in flavour creation by other categories, many whisky companies and commentators maintain that grain is a unique case. Somehow, what might be true for Cognac or mezcal can’t be true for whisky. And yet, a growing body of peer-reviewed evidence suggests that this isn’t the case at all.

Conversely, even when speaking to distillery managers and whisky makers off the record, few report any significant aromatic variation when switching from, say, French-grown barley to English- or Scottish-grown. Sure, grain quality may vary, in terms of nitrogen content, grain size, how it mills, and predicted spirit yield, but wild variations in flavour don’t seem to be occurring in practice.

This leaves us in something of a conundrum.

It’s Schrödinger’s terroir: anecdotal and scientific evidence of the influence of grain’s growing location on spirit flavour both exists and doesn’t exist at the same time, and, oddly, it seems to exist more plainly when looked for. Critics might call this confirmation bias. However, other factors might be at play, and this is where things become even more complicated.

Due to the industrialised nature of modern farming, there’s a strong argument that the global use of broadly the same types of pesticides and fertilisers, combined with the homogenisation of global farming practices, have subdued or muted the natural variation we might otherwise expect to see. Because conventional farmers in Scotland, England and France might all agree on the ‘best’ way to grow the same variety of barley and the kinds of soils that variety will grow well in when managed using modern input methods, the inherent characteristics of local soils and their propensity to deliver terroir-driven variation might be being washed away. Think of it a bit like painting over a multi-coloured wall with a blank undercoat before applying a new single colour of paint.

The original inherent characteristics (in this case nutrients, microbiota, and local flora and fauna) are replaced with manufactured nutrients and conditions. Thus, a kind of consistent ‘terroir’ is being achieved: a man-made kind. Perhaps this is why conventional distillers report so little variation in the taste of their spirit when switching the source of their conventionally grown grains. (Also worth considering is that maltsters will generally mix grain from multiple sources, which may further obscure local variations in character.)

Meanwhile, terroir-focussed distillers are often using organically produced and/or single-farm-origin grains precisely so we can ‘taste the terroir’. One thing’s for sure: outright denial won’t get us answers, and we’re only going to find out the truth by looking for it.