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How to Tell If Cheddar Cheese Has Gone Bad

Here are the signs that a block of cheddar cheese in your fridge has “turned,” and when it usually happens.

There’s nothing like biting into a piece of sharp, mature cheddar cheese you’ve been keeping in your fridge when you get the midnight munchies.

A creamy, strong, and pungent cheese that goes well with practically everything, cheddar cheese is also one of the “heartier” cheeses out there, especially when it has been aged for a year or so.

But this aging process takes place under special conditions before the cheese is cut, vacuum-packed, and sold to cheese lovers like you and me. So does cheddar cheese last forever in your refrigerator when you take it home from the grocery store? Definitely not.

This is, after all, a dairy product. And while cheeses last a whole lot longer than milk or cream, they don’t keep forever and eventually go bad. How do you know when that’s the case with the piece of cheddar cheese in your fridge?

Cheddar cheese will usually keep for 3-4 weeks in your fridge. After, it slowly but surely goes bad. Signs that a block of cheddar has gone bad include mold stains on the surface, an off odor that wasn’t there when the cheese was fresh, and an excessively sticky, somewhat mushy texture.

We cover the details, along with everything else you need to know, below!

How to Tell if Cheddar Cheese Has Gone Bad

Determining when cheddar cheese has gone bad can be a little trickier than looking at the sell-by or best-by date.

For one thing, these dates after often “recommendations,” not red lines drawn in the sand that tell you to eat the cheese by 11:59 PM on the day before they supposedly expire.

That might sound a little crazy to people that have their entire life abiding by these expiration days like the gospel. But it’s the truth!

In recent years and for the same reasons, a lot of “expiration dates” have been changed completely to “sell-by” or “best-by” dates instead. That seems like a subtle change at first. But it makes a ton of difference.

Instead of telling you that the cheese is going to expire completely the second that calendar day rolls around, it instead lets you know when this one cheese will start to degrade, though it won’t be unsafe—or even unpleasant—to eat for a little while longer.

Remember that, these days, expiration dates are more recommendations than anything else. They offer a great guideline to stick to, but there are a couple of things you’re going to want to do to make sure that your cheddar cheese really is going bad.

Look for Suspicious Spots and Stains

So, if the expiration date isn’t as informative as some of us think, how can you determine if cheddar cheese has spoiled or not?

Start off with a visual inspection.

While it isn’t at all uncommon for cheese, especially blue cheese, to grow mold, your cheddar cheese probably came to you with a uniform color and a uniform appearance, and for a good reason.

The mold on blue cheese is considered “good mold,” meaning the kind that won’t get you sick. The same can’t be said for the mold that grows on cheddar cheese when it starts to slowly but surely go bad.

If you start to see moldy spots or green to blue stains on the piece of cheese that you can’t explain, the odds are pretty good that your cheese is starting to “turn.”

But don’t toss your cheddar just yet!

You may be able to cut and carve out those spots and stains and salvage your cheese for a little longer. The rest (should) still be okay to eat, as long as any of the other things we highlight below aren’t present.

“If you see mold on the outside of hard cheese like parmesan or cheddar, cut away at least one inch of the cheese around and below the mold to salvage the cheese,” Michelle Dudash, Registered Dietitian Nutritionist, tells the Ohio Academy of Nutrition and Dietetics’ EatRight.org.

Give the Cheese a Good Sniff

Cheddar cheese—really good cheddar cheese, anyway—has an astringent smell with a certain creaminess to it that you will recognize almost immediately. That smell, while sharp, should never hint at spoilage and/or come off as off-putting.

If you start to notice an off odor coming out of your cheddar cheese, the type of odor that signals spoilage, the chances are pretty good that the cheese has started to go bad (and your nose is hinting to you exactly what’s going on).

Sometimes, this off odor presents itself as spoiled milk and tainted dairy, something that most of the unpleasant experience of smelling at least a handful of times in our life. (Typically, with milk after we have already poured ourselves a big bowl of cereal!)

Sometimes, though, cheddar cheese can take on an almost ammonia like smell. As soon as that pops up, it’s time for your cheddar cheese to make its way to your garbage bin ASAP.

Certain cheddar cheeses have the ability to sponge up smells and aromas from the rest of your refrigerator if they aren’t wrapped up in butcher paper and sealed away in food storage containers with the lid shut.

Hopefully, you are storing your cheddar cheese correctly, and this won’t be a problem. But if you do start to notice these “off smells,” it might not be a sign that your cheeses are bad so much as it’s a sign that your cheese has been in the fridge for a decent stretch of time.

Proceed at your own risk when the cheese has a funkier smell than it is supposed to. Never forget that the bacteria that cause spoilage in food can also give you food poisoning.

What Kind of Texture Are You Dealing With?

The texture of your cheddar cheese can let you know if it’s safe to eat as well.

You have to be a little bit careful with the “touch test,” though. This should be used as a sign that things are starting to go sideways rather than the be-all, end-all decision-maker about whether or not your cheese is still good to eat.

If you have noticed that your cheddar cheese just doesn’t feel right in the hand, doesn’t have the same kind of resistance when you slice it, or either feel really dry and hard or excessively mushy and sticky, the odds are pretty good you’ll want to pitch in and get a different block.

Cheddar cheese that has been left out or wrapped in a refrigerator will generally dry out and become hard, especially at the edges and around the perimeter.

Cheddar cheese that has gone bad—real bad—can sometimes get soupy in the middle, though it’s going to have a funky smell and a weird look to it long before that.

How Long Has the Cheese Been in the Fridge?

Cheddar cheese should be kept in the refrigerator and, to maximize its shelf life, shouldn’t be left to sit out on the counter for longer than 1 or 2 hours at room temperature.

Not necessarily down in the coldest portion at the bottom of your fridge but definitely in the fridge rather than out on your countertop. Quite a few folks keep their cheeses in food storage containers in the crisper drawer, which we consider a good idea.

You might want to make it a habit of tracking how many days your cheese has been in your refrigerator, though. As a general rule of thumb, cheddar (after it has been popped out of its factory package or airtight wrapper) will last about 3 to 4 weeks in the fridge before it starts to get funky.

It might be able to get a little more out of your cheese than that—maybe 5 or 6 weeks—but if you have a warmer refrigerator, you might only get 3 weeks out of your favorite cheddar block.

Track the time it’s spent in refrigeration, though, and you won’t have to play a game of guesswork anymore.