Here's How Long It Takes For That Opened Can Of Spam To Go Bad

Spam's got a reputation for being a mystery meat with a long shelf life, but the truth is, it's way less of a science experiment and more of an exercise in food preservation. It only has six ingredients, which are pork with ham meat added, salt, water, potato starch, sugar, and sodium nitrite. You're presumably familiar with the first five ingredients; the sodium nitrite is used as a standard food-safe preservative to extend the shelf life of the canned meat staple. (Which is delicious, thank you very much — I have a bunch in my pantry right now.)

That being said, its preservatives and canning method gives Spam a pretty generous lifespan of anywhere between two to five years on the shelf, which isn't atypical for a shelf-stable good. As a general guideline, Hormel does highly recommend you pop that thing open by the "best by" date printed on the bottom of each can for the best eating experience. You probably already know this based off discourse from the past few years, but those best by dates aren't a hard rule that mean you need to toss the food once the date has passed; expired canned food is almost always fine, but the older it gets, the older it'll probably taste. Once you open that can of Spam, however, you only have a few days to use it.

Spam does pack a ton of flavor, primarily salt, which is why I use it with a relatively sparing hand in my cooking. This typically means I have at least some left to store in the fridge for later. 

First off, I can tell you out of personal experience: Spam does eventually go bad once you open it. If you're someone who perpetually shoves stuff to the back of the fridge, discovering a lump of pink and mottled green and blue meat is not exactly the joy you imagined it might possibly be. How long I'd accidentally kept it back there will be a mystery lost to the sands of time, but the USDA would say I should have kept it in there for three to four days, not, like, weeks to possibly, uh, months.

The USDA also advises that even though it's safe to store the meat in its original container (just make sure to wrap the top!), it'll taste better if you transfer it to an airtight storage container. I tend to tightly wrap mine in plastic wrap, ensuring the meat gets the least amount of air exposure possible. But knowing I shouldn't let leftover Spam sit around in my fridge for a long time is just a good excuse for me to eat all of it faster, which is a problem I might actually enjoy.