Made from unpasteurized cow’s milk, and with an extra-hard texture, Parmesan cheese is the perfect topping for pizza and pasta dishes, and even tastes delicious in a healthy Caesar salad.
Pale yellow in color, this Italian cheese is aged between 12-36 months. If you have some that’s been sitting around in your fridge for quite a while, you might be wondering if it ever goes bad, and if so, how long it lasts.
The short answer is yes, it does go bad. The length of time it takes to spoil, however, depends on whether you have a block or have bought pre-grated or shredded cheese.
How Long Does Parmesan Cheese Last?
A block of unopened Parmesan can last between 7 and 9 months. It is always a good idea to check the best-by date when buying though, as this will give you some indication as to how long you can store it for. Want to know the best part? It should still last a few weeks after the best-by date!
If your block of Parmesan is opened, it can keep its freshness for approximately 6 months, but try to eat it between one and two months for ideal taste quality.
A packet of grated or shredded cheese doesn’t last as long as a block. Again, remember to check the best-by date, but usually an unopened packet should go on for a week past that date. If opened, eat within 3-5 days for excellent taste quality. You could even stretch it to about seven days, although the taste may not be quite as perfect at that point.
How Do I Know My Parmesan Cheese Has Gone Bad?
The clearest sign your Parmesan has gone off is if spots of mold appear on the surface. But it does get better! Because Parmesan is a hard cheese, it’s easy to remove small bits of mold and eat the good parts.
If there is too much mold, however, it’s safest to take no risks and discard the whole thing.
Grated Parmesan is a slightly whiter color than a block. If it has gone bad, it’s easy to tell—just watch the color! If it’s turned a yellow or dark beige, it has spoiled and it’s time to throw it in the trash. Be wary of the smell too—anything that’s gone bad will give off a nasty smell.
For shredded cheese, check the texture and, of course, the smell. If it feels damp, throw it out.
If mold appears in a packet of pre-grated or shredded Parmesan, chuck out the whole thing.
How Do I Store Parmesan Cheese?
To keep a block of Parmesan fresh for as long as possible, store it in the fridge and leave it unopened until you need to use it. When it comes to an opened block of cheese, you have a couple of options:
Wrap the pack in aluminum foil or cheese paper.
Pop it in a Tupperware box.
Put it in a freezer bag, making sure as much air has been squeezed out before sealing it tight shut.
Here’s the deal: make sure access to air is restricted as more air means your Parmesan will degrade faster. So for best results, storing your cheese in a freezer bag is your safest bet. Use Tupperware as a last resort as it may not be as effective as other methods since there is more air surrounding your cheese.
For an unopened packet of grated or shredded cheese, store as you found it in the supermarket. For example, keep it refrigerated if it was already in the fridge when you bought it. Or store it in a cool, dry, dark cupboard if, upon purchase, it was on a non-refrigerated shelf.
Once opened, always store it in the fridge and ensure the packet is tightly sealed.
What’s The Bottom Line?
Because the aging process is fairly long (12-36 months), so too is the shelf life of a block of Parmesan cheese, making it very easy to keep for some time providing you store it in your fridge—otherwise it will spoil quicker than the best-by date! Don’t forget the different guidelines for grated and shredded cheese, and enjoy it as a topping in your favorite Italian-inspired meals!