Popcorn is a curious food because it is not really food. Popcorn is pure carbs, and for that reason people love it. If you ever need quick, easy energy, or something to get your jaw moving while you focus on something else (usually a movie at a theater), then popcorn does just fine. So, how long does it last?
Popcorn does expire, but it can last a very, very long time, as far as foods go. Popcorn holds in moisture for between eight to twelve months. Does this mean it only lasts for eight to twelve months? Not exactly. In fact, it technically “lasts” longer than that, though not in a way that will make it taste good.
So, Does It Go Bad Or Not?
You see, popcorn is (as you may have heard) made of corn. Corn is starchy, and starch crystalizes when it is dry. When popcorn goes bad it is because they go stiff and stale, like how a cracker goes bad. This is because of their starchy corn molecules, which crystalize after a certain amount of time.
Most people do not actually know what it means for something to crystalize. How it works is that molecules exist in certain shapes. The shapes the molecules of a popcorn kernel, for instance, determine how soft it is, as well as how much heat can pass through it and how quickly, as well as other things.
Crystallization occurs when the molecules of the popcorn runs out of gluten, where the starch molecules get their water. Essentially, starch needs water, gluten provides water, but it can only provide so much before drying up. This process of “drying up” can take a long, long time, however.
It usually starts at around the eight month mark. After that, any eight month or older popcorn you pop will be dryer and dryer once it is popped. At around a year, the popcorn will be about as dry as it can get. This dryness will not make the popcorn inedible, nor will it make the popcorn unsafe. It just will have no taste.
How To Keep It From Actually Going Bad
As you might have noticed, something being dry and tasting bad does not exactly make it inedible. If you have low standards, not a lot of time, or a college student’s budget, then you might not care if it tastes good. Well, lucky for you, bagged popcorn practically never goes bad. This might be hard to believe, but it is true.
You have likely heard of high fructose corn syrup, but perhaps you do not know what it is. High fructose corn syrup is a preservative and a sweetener. It is derived from corn, obviously, and without much modification it has completely revolutionized the food science industry.
In the past there have been sweeteners like sucrose, which is derived from sugarcane. There have been preservatives, like gluten, which is derived mostly from wheat (although it can come from many places). But few chemicals can serve as both sweetener and preservative.
High fructose corn syrup exists at this intersection, which makes it one of the most important chemicals of the 20 and 21st centuries. Americans love sweet things, and we love being able to go to the store and pick out foods with far-flung expiration dates. Corn syrup provides both of these things while itself being easy to make.
This is due to its heritage with genetically modified corn. Corn as it exists today is completely unrecognizable from corn as it existed when native Americans were first planting it in prehistoric times. Corn stalks used to resemble peas in a pod, with no more than a dozen kernels of corn for every stalk of the vegetable.
Drive down any road in Kansas or Iowa and you will see how much this has changed. Corn has been adapted to a human environment, and humans have adapted to a corn-rich environment. Miles upon miles of it is grown, with hundreds of kernels on every stalk, all of it lasting far longer than it would in a state of nature.
This is why popcorn never really expires, even after its flavor has long disappeared. As long as it is kept in an airtight container, most bags of popcorn will likely outlive every human that currently exists.
How Long Does Popped Popcorn Last?
Popped popcorn lasts two to four weeks if kept in an airtight container. There is no need to overthink the storage of popped popcorn though; it does not require a refrigerator to cool it, or a freezer to freeze it. Just keep it in a ziplocked bag and it should last for quite a while.
Unlike popcorn kernels, popped popcorn can actually go bad. This will happen very slowly, but eventually it will grow moldy like an old cracker. Rest assured though, you will know when it happens.