Location, Location

Does the location of the maturation warehouse contribute to the flavour of mature whisky?

The general view of the Scotch whisky industry is ‘No’. For example, Diageo, which tankers much spirit from distilleries all over Scotland to be casked and stored in its vast warehousing complex at Blackgrange near Alloa (6 million casks), maintains that the Scottish climate is basically ‘maritime’, so it makes no difference whether Caol Ila is matured in Central Scotland (which it is) or on Islay.

Many distillers take a different view, some making a virtue of the location of their warehouses – Bowmore, Ardbeg and Laphroaig are typical examples; Talisker’s slogan is ‘Made by the Sea’. But all acknowledge that there are many more important factors which influence maturation, especially the cask (American or European oak? First-fill or refill?).

The factors associated with location which may influence the flavour of the whisky are all to do with climate. Although Scotland’s climate is described as ‘cool, temperate and maritime’ there are subtle variations across the country. The west is milder and wetter than the east; the Highlands are generally cooler than the Lowlands, with greater seasonal variations in temperature; islands and coastal regions are more windy than inland areas.

Temperature changes cause the spirit to expand and contract: warmer warehouses mature their contents faster than cooler warehouses, and there are less temperature variations in traditional dunnage warehouses (low, earth-floored, usually stone-built) than in racked warehouses, where the casks may be stored up to twelve high.

The former are generally cooler and damper than the latter, so there is less loss of water vapour during maturation. HMRC allows for 2% per annum loss of volume. Humidity changes what evaporates from the cask (the ‘angels’ share’). In extreme cases of high temperatures and low humidity the loss of water vapour may lead to an increase in alcoholic strength. This is rare in Scotland but not uncommon in Kentucky and in some Indian locations, where that angels’ share is correspondingly much greater – up ton15% in some cases.

The microclimate of individual warehouses can be a considerable influence and even within the same warehouse cask can age differently. The maturation of casks stored low down where it is cooler will be slower than those stored high on a rick or on the upper floors of a warehouse where temperatures are generally higher. Subterranean streams running beneath a warehouse increase the humidity immediately above them. There is just such a stream which runs diagonally across a warehouse at Talisker distillery and visibly influences the casks above. Some distilleries intentionally rotate casks to even out the effect, especially in the U.S.A.

Finally there is the thorny question of maturation close to the sea introducing salty flavours to the mature whisky. Some chemists maintain that it is impossible for sodium chloride to penetrate the walls of the cask, but there is no doubt at all that some malts have maritime, saline characteristics, and many such whiskies are matured close to the sea – the aforementioned Bowmore, Laphroaig and Talisker, for example, but also Pulteney, Glen Scotia and Isle of Harris. But by no means all: Glenmorangie, Scapa, Jura, Bunnahabhain and Bruichladdich are all matured on the coast but have no obvious maritime character.