So, you’ve taken the plunge and splurged on a big bottle of your all-time favorite scent, the classic Chanel No. 5.

You take it home and, after an inaugural spritz, place it gently on top of your dresser, right in front of a lovely picture window, where it will be displayed for years to come. But then a terrible thought suddenly springs to mind. Wait — will this perfume expire? Will I be able to finish the bottle, or will it spoil before I get my money’s worth?

The hard-and-fast answer: Yes, perfumes do expire. It all depends on the scent’s chemical composition, but they do tend to break down and oxidize over time. The scent changes, the perfume may darken in color and eventually it could become obvious that the perfume has spoiled. But there’s really no way to tell when any given scent will bite the dust. For every expert who maintains that three to five years is a good rule of thumb for perfume shelf life, there are dozens of people who claim to own 50-year-old scents that are still wearable. Some perfume-lovers encourage others to think of a scent like a fine wine — its flavors might change, but as long as it still smells good, why not wear it?

One thing we can say for sure, though, is that a picture-window place of honor will undoubtedly shorten the life of your Chanel No. 5. It stands to reason that you’d want to display it: You paid a pretty penny for it, and that iconic bottle was part of the price. It was meant to be seen, right? For some, wearing the scent is only half the effect of having the perfume — looking at the pretty packaging is part of it, too.

But unfortunately, sunlight, heat and humidity will speed up the deterioration process in a big way. So if you want your perfume to last, you need to store it in a cool, dark place. Room temperature, according to some, is even a bit warm. Refrigerators are too cold, but some serious perfume aficionados and collectors do store their treasures in dedicated mini-fridges set somewhere in between. For the non-obsessed perfume owner, however, a dresser drawer or closet shelf will do just fine. Keep the bottle closed tightly, and you’re doing all you can to ensure the longest life possible for your perfume.