Bacon is delicious. It is also perishable. What is sadder than uneaten, uncooked bacon that you have to throw out? Contracting some food-borne illness from bacon and being unable to eat bacon with the same gusto as before. (And before you sit down to house 100 strips of bacon before their expiration date, remember that, yes, there is such a thing as too much bacon.) But there's a lot of misinformation out there about how long bacon can sit out of the fridge before it goes bad. Because it's a cured meat product, bacon can have longer shelf life than, say, a pound of ground beef. But it depends on what kind of bacon you have.
Here in the U.S., when most people talk about bacon, we're referring to the product that you can pick up at most grocery stores near the lunchmeats. This mass-produced bacon is heat processed in a large convection oven, rather than the traditional method of smoking the pork belly, because it cuts down the processing time from many days to just about 6 hours. Before being popped in the oven, this bacon is cured with salt and nitrates. After both these steps, the bacon is sliced for packaging and quickly chilled to below 40 degrees Fahrenheit in order to stymy bacterial growth.
This kind of bacon usually has an expiration date stamped on the package, which you should definitely check before you buy or consume it. Once the package is opened, the FDA recommends that you use or freeze the bacon (yep, you can freeze bacon) within seven days to ensure freshness. If unopened, the Food Marketing Institute recommends using the bacon within a month. Even if you freeze the bacon, its high fat content makes it susceptible to developing rancid flavors (ew) and the quality and flavor of the meat will deteriorate the longer you store it. How to tell if bacon has gone bad? Pay attention to the way the bacon looks. If it has changed color to green-ish, or grey-ish, or has mold spots, that bacon has gone bad, my friend. Another good marker is the way the bacon smells. If it smells off or rotten, toss it. As painful as it is to throw bacon away, it's definitely better than getting sick.
The general, culinary school rule of food safety for raw meat is that you don't let things sit out more than four hours. For raw mass-produced bacon, that's probably a good rule of thumb. It's wise to be extra careful with raw pork products because of a not-so-fun illness called trichinosis, a particular risk with undercooked pork and wild game, which causes vomiting, fever, fatigue, and abdominal pain. For cooked bacon, you have quite a bit more lee-way. After cooking, refrigerate and use within four to five days.
But not all bacon is the mass-produced kind you find next to Lunchables. If you get your hands on dry-cured bacon, that lasts much longer, even outside of the fridge. Unlike mass-produced bacon, dry-cured bacon is made by curing the pork for days, and is thus much more resistant to bacteria. The USDA recommends using dry-cured sliced bacon within ten days when unrefrigerated, and within four weeks if you keep it in the refrigerated. If the dry-cured bacon comes in a slab—the kind you slice yourself—it can last up to three weeks without the fridge, and four to six weeks in the fridge.
If you have worries about a bacon-adjacent product, like bacon bits, canned bacon, baby food with fresh bacon, or turkey bacon, have no fear—the USDA has a handy chart of bacon storage recommendations for all those products. Yes, it's lame that bacon goes bad. But the good news is that it gives you incentive to eat bacon when you have it.