Does Whisky Go Off?
The top three whisky questions I get asked in the bar;
Whta’s my best whisky?
What’s my favourite whisky?
Does whisky keep ageing in the bottle and does it ever go off?
The first two questions I’ll address in later blogs but today, let’s talk about what happens to whisky once it hits the glass.
How Bottled Whisky Ages—and How to Store It
Whisky is often thought of as eternal—something to be opened decades after bottling and still enjoyed, unchanged. That’s mostly true. But like all things, whisky has its limits. While it doesn’t spoil like milk or go “off” in the traditional sense, there are conditions under which its character can degrade. So how long does a bottle of whisky last? And how should you store it to keep it at its best?
Age Stops at the Bottle
Let’s start with one of the most persistent myths in whisky: that a 12-year-old bottle sitting unopened on a shelf for another 20 years somehow becomes a 32-year-old whisky. It doesn’t.
Whisky ages only while it’s in the cask. That’s where the transformation happens—through interaction with wood, oxygen, and time. Once it’s bottled, the ageing process effectively stops. The spirit you seal is the spirit you keep. An unopened bottle of 12-year-old whisky remains a 12-year-old whisky, even if it sits in your cupboard for half a century.
Shelf Life of an Unopened Bottle
If stored correctly, an unopened bottle of whisky can last for decades without significant loss of quality. The high alcohol content (usually 40% ABV or higher) acts as a natural preservative. As long as the seal remains intact and the bottle is kept away from extreme heat or light, the whisky inside should taste as intended for many years.
That said, minor changes can still occur over time due to tiny amounts of oxygen ingress through the seal or chemical changes within the whisky itself. These shifts are often slow and subtle—some enthusiasts even claim older sealed bottles take on unique characteristics. But in general, properly stored unopened whisky remains stable.
What About Opened Bottles?
Once a bottle is opened, it begins a very slow process of oxidation. Exposure to air, especially in bottles that are half-empty or less, can gradually alter the aroma and flavour. While some oxidation can actually open up a whisky’s character, too much can lead to dullness, bitterness, or loss of complexity.
As a general guide:
A nearly full opened bottle will stay good for 1 to 2 years.
A half-full bottle might hold up for 6 to 12 months before noticeable changes.
Less than one-quarter full, ideally you’ll want to finish it within a few months.
(This being said, I’m writing this while sipping on a glass of Starward Peated Finish from a ¾ empty bottle that I opened at least 12 months ago and it’s still a perfectly delicious drop.)
Storage Tips
A guide to keep your whisky at its best:
Store upright – unlike wine, whisky should not lie on its side. Prolonged contact with the cork can degrade it.
Avoid heat and light – keep bottles in a cool, dark place to prevent flavour deterioration and evaporation.
Keep it sealed – tightly recapping the bottle after each pour helps limit oxidation.
Consider decanting – for long-term storage of opened bottles, decanting into smaller containers can reduce the air-to-whisky ratio and slow oxidation.
Final Thoughts
Whisky may not age in the bottle, but it certainly holds its character—if you let it. With a little care, your favourite dram can remain just as enjoyable years after you brought it home. So don’t worry if your shelf’s a little crowded. Just store it well, pour it when the moment’s right, and savour it slowly. That’s the point, after all.