Now that you’ve purchased your first bottle of premium aged whiskey, what steps should you take to preserve it for as long as possible? The good news is that unopened bottles of whiskey really never go bad – they have a high enough alcohol content that the alcohol acts as a preservative. Thus, as long as you don’t open up your bottle of premium whiskey, you don’t have to worry about it spoiling, going bad, or becoming stale. It’s an entirely different matter, though, once you’ve actually opened up your bottle of premium whiskey.

As a general rule of thumb, the more air that is exposed to your whiskey, the faster it will degrade. However, the rate of whiskey degradation is nowhere as near as fast as what you’d encounter with beer or wine. In other words, even if you open up your bottle of premium whiskey to enjoy with family during the holiday season, it’s quite conceivable that you could drink the same whiskey the following year, as long as you take the necessary precautions (more of that later).

So how long do you really have before you start to notice a loss of flavour? The rule that most people follow is that a half-full (or half-empty, depending on your perspective) 750 ml bottle of whiskey will last for a year before it begins to lose flavour. That’s a full 12 months! Moreover, it is only at the two-year mark that the level of flavour loss becomes serious enough that you really can’t enjoy it anymore.

The real problems come, however, the closer you get to the bottom of the bottle. For example, if you are talking about a 750 ml bottle that is now one-third full (and not one-half full), then you only have about three months before you begin to experience a loss of flavour. It’s important to note here that the rate of degradation actually speeds up, the closer you get to the end. That’s because the proportion of air to liquid in your bottle is changing, and as soon as you hit the halfway point, there is more air than liquid in your bottle.

Protect your whiskey against contact with air

That leads us to our first rule – do everything that you can to protect your whiskey against contact with air. The air will oxidize your whiskey, which in turn will cause the breakdown of chemical compounds within your whiskey. As they compounds degrade, that is what leads to the loss of flavour.

When a bottle is not yet opened, the combination of the stopper and the wax, plastic or foil seal around the top of the bottle will prevent air from entering the bottle. There may be a tiny amount of air trapped in the whiskey bottle at the time of bottling, but not enough to cause any serious effects. Moreover, the shape of the bottle protects against oxidation – there is less surface area for direct contact in the stem of the bottle. As you drink more and more of the whiskey, however, you are allowing air to interact with a greater and greater surface area of the whiskey. To deal with this problem, some whiskey lovers will transfer the last one-third of their bottle to another, smaller container and then re-seal it, to prevent further oxidation.

Protect your whiskey from light

Next to air, the next biggest culprit in the degradation of whiskey is light. The UV rays in light will break down the tannins in the whiskey, causing it to lose much of its full expression. As a result, you should never store your whiskey in a place that has direct contact with sunlight. For that matter, you should never store your whiskey in a place that has contact with the light of any kind.

Of course, there are various ways to mitigate the impact of light. Bottlers, for example, will use green, brown or black glass in order to protect the liquid from light. And many whiskey lovers will store their whiskey in a dark place, such as a liquor cabinet.

Yet, keep in mind – liquor stores keep their products out in light all day, and there is little or no effect over the long term. The rate of degradation associated with daily light is less severe than the rate of degradation associated with exposure to air.

Protect your whiskey from heat

One risk that stems from exposure to heat is evaporation. During this process, whiskey will lose some of its alcohol vapour. And keep in mind – alcohol evaporates more easily than water, due to the fact that it has a lower boiling point than that of water. So prolonged exposure to heat (such as sunlight during the warmest months) will speed up the process of evaporation, and cause a degradation of your whiskey.

The good news here is that a solution is very easy o find: simply keep your whiskey in a cold, dark place. If you don’t have a cellar or basement, then try a dark liquor cabinet at room temperature. You just want to avoid the effects of too much-sustained exposure to heat.

Be careful with the way you display your whiskey

As the owner of a premium whiskey, it’s only natural to be proud and want to display it to everyone who visits. That makes sense, and it’s also very much possible, as long as you take certain common-sense steps. For example, you will always want to display your whiskey standing up, rather than on its side (as you might a bottle of wine). The reason is that any exposure of the liquid and the stopper (and especially a cork stopper!) could lead to the imparting of unwanted flavours to the whiskey.

At the end of the day, whiskey is remarkably resilient and will last a long time  - and perhaps even forever – as long as you don’t open it. Once you do decide to enjoy the whiskey, though, that’s when you will have to take the necessary measures to make sure that it is not being exposed to air, light or heat. So feel free to open up that bottle of whiskey and enjoy it with friends this year – don’t worry, even if you don’t finish, you’ll still have at least another 12 months to enjoy it fully.

Image credit: Macallan on Instagram (@USmacallan)