A lot of people ask us, “How long can an unopened bottle of whiskey last?” It’s a good question. Under the right circumstances, the answer might very well be “almost indefinitely.” How can we say that? Because a few cases of whiskey managed to survive, virtually unchanged, for over a century.

From 1907 to 1909, Ernest Shackleton and a group of explorers managed to set a new record while attempting to reach the South Pole—getting within 97 miles of the destination. Before they set out on their hike though, they left a cache of supplies in a hut on Ross Island. Hidden beneath the floorboards were several cases of whiskey.

In 2007, Members of the Antarctic Heritage trust discovered these lost treasures. And several bottles were sent to Scotland for tasting and analysis. The verdict? By all accounts it was still delicious and hadn’t deteriorated at all over the course of a century. But storing your whiskey beneath a hut nestled in Antarctic permafrost isn’t always an option for everyone.

So how can you make sure your unopened bourbon keeps perfectly? Under less extreme conditions, it’s not unreasonable to expect a properly sealed bottle of whiskey to retain its flavor for many decades, as long as it’s stored under consistently favorable circumstances.

Light and temperature variation are the two factors you really have to watch out for. Either can catalyze chemical reactions within your whiskey, which will slowly break down the esters that give the spirit its flavor and character. It’ll still be the same proof—that won’t change, but it will taste like a pale ghost of its former self. Cabinets are a safe bet, but basements and cellars are even better for long-term storage. Always remember, consistency is crucial.