Can You Eat Expired Parmesan Cheese & Does it Go Bad?

This article may contain affiliate links (disclosure policy).

Date labels serve as a general guideline for the freshness of food products including cheese.

This naturally brings the question if you can use or eat unopened expired parmesan cheese.

The answer to this question will mostly depend on the way parmesan was stored and its present quality.

Even though hard cheeses such as parmesan have a long shelf life, they can still spoil if they’re stored improperly.

In this article, I’ll explain how long parmesan cheese can actually last and if you can use it when it’s past its prime.

Can you still use expired parmesan cheese?

Date-labeling phrases are a tool that the USDA uses to determine the quality of cheese and other food products.

Parmesan cheese is typically marked with labels such as “Best before”, “Best if Used By”, “Use-By” or “Sell-By”.

Even though the meaning of these phrases should be self-explanatory, many people misinterpret them as safety dates.

Put simply, the expiration dates on parmesan cheese tell us the last date at which parmesan is of peak quality.

As you might assume, this doesn’t give us any information regarding the safety of expired parmesan.

So does this mean you can eat parmesan cheese after its expiration date?

Expired parmesan cheese can still be safe to eat as long as it doesn’t show any signs of mold growth. Therefore, you should always inspect its quality to make sure it’s not contaminated with bacterial or fungal microorganisms.

With that said, the quality of parmesan, whether it’s grated or not, will start to diminish after its expiration date.

That’s why it’s a good idea to buy it in small quantities and use it while it’s still fresh.

Does parmesan cheese ever go bad?

Regardless of the way you store it, parmesan will slowly start to absorb moisture from its environment.

As time goes on, this will increase water activity and create suitable conditions for microbial contamination.

So in essence, parmesan cheese will eventually spoil even if it was stored under perfect conditions.

How long is parmesan cheese good for?

The amount of time you can keep parmesan cheese before it spoils, depends on its type and storage conditions.

According to the USDA, unopened parmesan cheese can last for 6 months in the fridge before it goes bad.

This guideline applies to both grated parmesan and parmesan that’s sold in blocks.

Having said that, parmesan cheese will last for 1 month in the fridge after opening.

You can also keep parmesan at room temperature, but its shelf life will be significantly shorter than if it was stored in the fridge.

And since there aren’t any official storage guidelines, you’ll need to regularly inspect it for mold growth.

It’s also worth noting that the recommendations provided by the USDA give approximate storage times.

This means that it’s quite possible for parmesan to still be good even if it exceeds them.

Therefore it’s a better idea to inspect parmesan for signs of spoilage before tossing it out.

To do this, you simply need to check its color, texture and smell.

One of the clearest indicators that you need to discard a block of parm is the presence of black, green or blue spots.

These typically point to mold growth which in itself can lead to food poisoning.

In terms of texture, there shouldn’t be any unusual changes such as the presence of slime. If your parm seems slimy or gooey, then it’s best to toss it out.

The last thing you can do to check if your parmesan is beyond salvation is to give it a whiff. In case you sense a sour or musty odor then you should probably replace it.

For example, although it looks old the following photo shows a block of parmesan that’s perfectly good for consumption because it lacks any of the signs I listed above:

a chopped parmesan block that's still good for consumption

Related Read: How Long Can Unopened Milk Stay Out at Room Temperature?

What happens if you eat expired grated parmesan cheese?

The date labels employed by the USDA can create a bit of confusion when it comes to the quality of parmesan cheese.

As we’ve already established, these labels are used to denote when parmesan is at peak quality.

This essentially means that it will still be safe to eat provided that it doesn’t show any signs of spoilage.

So even if you ate grated parmesan cheese that has expired, you won’t experience any ill effects as long as it hasn’t spoiled.

If however you consume spoiled parmesan cheese, you might experience a variety of symptoms ranging from mild to severe.

In mild cases, you might feel a bit nauseous or experience some stomach cramps. These will usually pass away without requiring any medical assistance.

In more severe cases, you might experience symptoms such as diarrhea, vomiting or fever. In case you’re having any of these symptoms you should contact a doctor and seek medical help.

Wrapping up

If you’re feeling hesitant about giving that block of expired parmesan cheese a try, then now is the time to do it.

Parmesan cheese can still be used after its expiration date has passed as long as it isn’t spoiled.

Just remember to give it a thorough examination before you incorporate it into your dishes.

Here’s a couple of recipes that use parmesan cheese in case yours is still good for consumption:

If you've tried my recipes and cooking tips, please tag me on social media - I would love to see your creations! 

Following me on PinterestYouTube or Facebook may be just a click for you but it's very valuable to me... So thank you for your support!

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.