Of course when it comes to whisky, bottle maturation does not officially exist. The age statement refers only to the years in wood. What happens thereafter is considered irrelevant since all the flavours and aromas created in the new-make spirit and evolved in the cask are locked in at the time of bottling, never to change.
But I have my doubts. I think some whiskies probably do evolve very slightly if left in a bottle for long enough. Of course I cannot prove this, but neither can those who take the official line. To do so would involve time travel and the ability to taste something straight off the bottling line and then fast forward through the decades to taste it again a few seconds later.
Personally I suspect the dogmatic line on bottle maturation stems from the industry’s age-old obsession with consistency. For years we were told how the likes of White Horse blended Scotch were a constant in a changing world. Yet with distilleries swapping hands, falling silent and occasionally disappearing, the recipe for any blend has always been a moveable feast.
Similar variations exist in single malts. If in doubt visit the Vintners Rooms in Edinburgh where you can taste part of Giuseppe Begnoni’s vast collection of whiskies dating back to 1901. A Glenlivet 15 Years Old bottled in 1972 that I tried recently certainly had more depth and complexity than the current release, though it is impossible to say if any of that was due to spending 40 years in glass.
Another sceptic like me is Richard Joynson of Loch Fyne Whiskies who has spent years experimenting with a living cask: a vatting of several malts which are topped up whenever it becomes half full. This solera system creates a unique and ever-changing whisky and Joynson’s theory is that the component parts of a vatting or blend are very slow to fuse together. With the living cask of Glenlivet and Brora created for Loch Fyne’s 10th anniversary he says: “The bottles have changed in character since we started selling it, the peatiness has gone down.”
But perhaps the simplest and best argument for saying that bottled whisky can alter over time concerns the issue of storage. If the character of Scotch is set in stone when sealed under a screw cap or cork stopper, then it would not matter where you stored it.
No stopper is a perfect seal and as a result old whiskies will eventually lose alcohol and volume through evaporation, so it is worth asking what else might be happening inside the bottle. Giuseppe Begnoni believes it depends on the bottling strength. He told me that a whisky that was originally 43% may be no good if it has dropped to say 40%, whereas a similar fall in a cask strength bottling “may even improve the whisky and make it a little softer.” Once again this is impossible to verify, though that is the beauty of this unresolvable debate.
But what of that most famous example of ancient whisky that accompanied Shackleton to the South Pole? Sadly the great explorer cannot come back from the grave to taste his buried treasure and declare whether Mackinlay’s blend has changed after 103 years on ice.
The Shackleton whisky may be a bad example, since the stable sub-zero temperatures would have slowed any improvement or deterioration. Yet on the overall issue Paterson takes the official ‘no change once bottled’ line, before conceding that he has occasionally noticed “a slight mellowing effect and a slight loss of character” in some of the older bottles he has tried.
Who knows where the truth lies, but I would agree that any changes tend to be minimal certainly compared to wine. Luckily our beloved spirit is pretty robust.