For how long can you keep an open bottle of whiskey?
Whiskey is a distilled spirit and distilled spirits, unlike fermented alcohols such as wine, are very hearty. Whiskey in a sealed bottle can last decades, maybe even longer. Once you pop the cork, you are still good for a long while compared to wine, which needs to be had within days, but exactly how long will that Scotch or Bourbon last?
Answering this question is harder than you might think and there are different schools of thought. Once you uncork the seal and pour a glass, you let oxygen into the whiskey bottle so oxidation is a possibility. Just how long such oxidation takes and under what circumstances is not clear.
It is common lore among whiskey fans that once a bottle is half full or less, you should drink it within 18 months to prevent oxidation and a change in flavor. Others, however, swear that whiskey can last for years at a low level and have virtually no ill effects.
Well, I decided to find out a little more about the effects of oxygen on whiskey, so I set up a little experiment. I filled three mini bottles with varying levels of whiskey, in this case Longmorn, a single malt Scotch. I filled one to the absolute top such that no oxygen was left in the bottle, a second about half-way and a third about a quarter full. I will now store these bottles, in a cool, dark place, for two years. In early 2011, I will revisit them and see how they've done. It's a long time to wait, but the results will be interesting and will hopefully give us some clarity regarding this age old question.
While we wait, I'll give you my tasting notes on the Longmorn:
Longmorn, 16 year old, [owned by Pernod Ricard] 48% alcohol ($92).
Nose has light sherry and malt, very pleasant. On tasting, the first thing you get is a rush of sherry, followed by some sweetness and then a nice little whisper of malt. Mostly sherry on the finish. A mildly sherried Speysider that is pleasant but not particularly distinctive. I'd say it's overpriced for what it is.
Tune in around February 2011 and we'll see what the result of our ageing experiment is.
UPDATE: Results are in!