There’s a world of difference between a gut feeling and a knee-jerk assumption. You might believe that of the whiskies you’ve tried to date you have a preference for unpeated styles – but that’s far from stating that somehow you are predisposed to dislike all peated whiskies. Similarly I don’t believe that even once a whisky is in a glass, that it’s some form of monolithic substance – unchanging, inert and always the same no matter the time, the place or the imbiber. There’s a world of variables at play that can all affect how we judge (whether it be gut or knee-jerk) liquid – least of all, there’s oxygenation.
When you aerate alcohol, two processes occur – evaporation and oxidisation. Whereas wine, with its lower ABV can be influenced by both of these, when talking about spirits, we’re primarily focussing on the latter (at least in terms of the drinking experience, maturation and evaporation are a different topic for a different day). Think of oxidation as the same process that causes an apple to turn brown, or an iron nail to rust – the addition of oxygen to a compound causes it to lose electrons – and when that happens, there’s an accompanying reduction in one form or another. Many compounds contained in whisky are susceptible to oxygenation – from phenols through to ethanol itself which will convert into acetaldehyde and acetic acid (which you’ve probably heard of before – vinegar).
As oxygen is introduced into a whisky, the reductive process begins – initially breaking down the bonds between aroma and flavour compounds – which is why you might find some drams to be more expressive or pronounced after a period of glass resting. Similarly, some whiskies won’t benefit at all from aeration – or even worsen. Largely it’s a process of experimentation – and will undoubtedly be affected by your personal preferences – but, I’ve often found older whisky offers rewards for patience. What might seem entirely ordinary can become exceptional as the aromas and flavours gradually unravel in the glass following years of tight constriction either in the cask or the bottle.
Today’s review is not a random coincidence – it’s a whisky that I discovered was particularly disposed to the effects of oxygenation. Back in time to 1971 and over to Dallas Dhu in Speyside…
Dallas Dhu was closed in 1983 and is now a museum (with much of the old equipment still in-situ). You won’t see much Dallas Dhu around except for on auction sites. Indeed, it seems that independent bottler Gordon & MacPhail bought much of the stock of the distillery – most of the bottlings over the last 10 years (and there has not been any for the past four) have been produced by this bottler. Our G&M 1971 Dallas Dhu was bottled in 1995 for the company’s Connoisseur’s Choice range – which, during the 90’s featured old style regional maps. It’s delivered at 40% ABV (as all old map G&M’s bottlings were).
Nose: The historical nature of this bottling is confirmed by some initial serious OBE – overripe dusty pineapples and wet soiled floors in dunnage warehouses. This lifts after some minutes of resting to reveal an orange-fest – juice, peels, liqueurs - the whole caboodle – still surprisingly bright and tangy. Running throughout, brassiness and an edge of minerality, alongside damp cardboard boxes – not fully successful, but fascinating. Further resting adds in tea like qualities – steeped, slightly acerbic, with a touch of mint and olive oil. After 30-40 minutes in the glass, sourness levels reduce, and the nose now favours chocolate orange cake and ginger. A total shapeshifter.
Taste: The arrival has some nice cling for 40%, but is exceedingly saccharine – over sweetened honey, and a sugar-coated apple that’s got stuck in the sugar-coating machine. Puckering stuff. Aeration reduces this assault, but initially this results in huge sourness – Gueuze beer and niche Haribo. Miraculously, after further resting, there’s a recovery of poise and an offering of juicy tinned fruits (mangos and pineapple) and lemony polish. Supporting the chameleon fruitiness is bees honey - rich and heathery, malty cereals and dry sparkling wine. The mid-palate offers a textural change – slight chalkiness, verging on aspirin, that also adds left-field salinity and flintiness into the mix. The back-palate is more herbal with sage and touches of menthol.
Finish: Short to medium with white pepper, orange toffee and chalk.
This Dallas Dhu is one of the oddest whiskies I’ve tasted this year. But, it's also one of the most exciting. The aroma and flavour combinations are downright eclectic – at times they seem almost alien to one another, absorbing by themselves but isolated when taken as a whole. But, resting has a truly spellbinding effect here – not in terms of restoring a sense of balance, but in reaffirming just how much a whisky can change in the glass. There’s nary a moment when this dram is not offering up something new and different – in that sense, it has superb complexity. Whether the offering feels cohesive is another matter entirely, but regardless, the journey itself is mesmerising.