The Surprising Longevity of Grated Parmesan!

Beyond the Best Before: The Truth About Grated Parmesan’s Shelf Life!

Opened grated Parmesan cheese is good for about 4-6 weeks in the fridge if stored in an airtight container or tightly sealed original packaging. To prevent spoilage, avoid exposure to moisture and heat.

Once Opened, How Long Is Shredded Parmesan Cheese Good For?

Like most of us, I bet you buy larger packs of shredded parmesan, more than enough for one meal.

So, once you have opened it, how long is the parmesan good for?

Well, first of all, it does need to be refrigerated and preferably stored in an airtight container.

If that’s the case, you are looking at a period of about a week.

However, if you buy the parmesan as a whole block and only grate what you need, it will last much longer. 

It could still be edible for up to two months.

🧀 Creative Ways to Use Grated Parmesan Before It Spoils 🍴

Pasta ToppingSprinkle over your favorite pasta dishes for an extra flavor kick.
Salad SprinkleAdd a savory touch to salads, especially Caesar salads.
Baked GoodsIncorporate into breads or muffins for a cheesy twist.
Soup GarnishEnhance soups like minestrone with a Parmesan garnish.
Vegetable ToppingAdd to roasted or steamed vegetables for added flavor.
Brought to You by

This could be a more cost-effective way to buy your parmesan.

When the cheese is grated, it exposes more of its surface area.

So, as you can imagine, that gives more opportunities to attract bacteria.

Parmesan lasts a lot longer than other cheeses.

This is because it is classed as hard cheese; it has a low moisture content.

Moisture is known to be a breeding ground for bacteria, causing food to go moldy.

So, a softer cheese that contains more moisture is likely to go off quicker than parmesan.

How Do You Know if Grated Parmesan Has Gone Off?

Thankfully, there are several visual clues to indicate that your parmesan has gone bad.

The most obvious will be patches of blue or green mold.

But the overall color of the parmesan may also change. 

Fresh parmesan is very pale, almost white or a very light yellow. 

Once the cheese starts to deteriorate, it will become darker and more orange-colored.

The smell of parmesan is quite distinctive, and some find it unpleasant, as though it has already gone off!

So, relying on the odor of the cheese to indicate if it is still fit to eat may not be reliable.

You can also check the texture of the parmesan; it should flow freely and feel dry to the touch.

If it’s at all wet or feels spongy, it should not be eaten.

One thing to remember is that you shouldn’t just try and pick out any moldy pieces.

The mold spores are likely to have spread through the whole packet, even if you can’t see them.

So, unfortunately, you need to throw it all away to be on the safe side. 

The exception to this is if it’s a whole block of Parmesan.

In that case, you can just cut the moldy section off.

A photograph of a bowl of pasta with Parmesan cheese

Spotting the Spoil: Parmesan’s Tell-Tale Signs

When it comes to mold in grated Parmesan, it’s crucial to recognize the warning signals of spoilage.

Unlike whole blocks of Parmesan where you might simply cut off the moldy part and continue using the rest, grated Parmesan presents a different challenge.

The smaller pieces mean that mold can quickly spread throughout the container, often invisible to the naked eye.

If you notice any discoloration, typically a darker, orange hue, or spots of blue or green mold, it’s a clear indicator that your Parmesan has gone bad.

Understanding how to tell if Parmesan is bad goes beyond just visual cues.

A noticeable change in smell is another red flag.

Fresh Parmesan has a nutty and slightly fruity aroma, but when it turns, the smell becomes sour and unpleasant.

Texture changes too can be a giveaway.

Fresh grated Parmesan is dry and flows freely, but when it starts to clump together without any signs of moisture, it’s a sign of spoilage.

A common question is, do you have to refrigerate Parmesan cheese after opening?

The answer is a definite yes.

Refrigeration is essential to prolong the shelf life of grated Parmesan.

In the fridge, it maintains its quality and flavor, while reducing the risk of mold and bacterial growth.

Always store it in an airtight container to prevent exposure to moisture and other contaminants, which can hasten spoilage.

Being vigilant about these signs and storage practices will ensure that you can enjoy your Parmesan at its best.

Does Parmesan Go Bad?

Final Thoughts

  • Grated parmesan, once opened, typically lasts about one week if refrigerated in an airtight container. It’s similar to keeping leftovers from a pasta dinner; proper storage is key for freshness.
  • Whole blocks of parmesan cheese, when grated only as needed, can last up to two months. This is akin to buying a larger pack of coffee and grinding it as you use it to preserve flavor and freshness.
  • Grated parmesan exposes more surface area, which increases the likelihood of bacterial growth, much like how sliced fruits spoil faster than whole ones.
  • Signs of spoilage include a change in color to a darker, more orange hue, and the presence of blue or green mold, similar to how bread shows signs of mold when it’s past its prime.
  • Unlike whole parmesan, where you can cut off the moldy part, grated parmesan with mold should be entirely discarded for safety, as you would with a container of moldy berries.

Once grated parmesan is opened, it is unlikely to last more than a week. 

This is because there is more surface area exposed that could attract bacteria.

It should always be refrigerated in an airtight container.

However, a whole block of parmesan could last for two months.

You can recognize when parmesan has gone bad as it will either change color or have visible patches of blue or green mold.

Please don’t take any risks with your health.

If you have any doubts about your parmesan cheese, you need to throw it away.

If you are concerned about other cheeses, read my article on how to know if halloumi is safe to eat.

How might this article influence your approach to purchasing and storing Parmesan cheese?

Let us know in the comments below!

A photograph of a bowl of pasta with Parmesan cheese

FAQ: Grated Parmesan Cheese

Q: How long can I store grated Parmesan cheese after opening?
A: Opened grated Parmesan cheese typically lasts about one week in the fridge when stored in an airtight container.

Q: Is it better to buy grated Parmesan or grate it from a block?
A: Grating Parmesan from a block as needed can extend its freshness up to two months, offering better value and flavor retention.

Q: Can I eat grated Parmesan cheese after the expiry date?
A: It’s not recommended to consume any cheese past its expiry date, as the risk of spoilage and foodborne illness increases.

Q: What are the signs that grated Parmesan cheese has gone bad?
A: Look for a change in color to a darker, more orange hue, and the presence of blue or green mold as indicators of spoilage.

Q: Can I just remove the moldy part of the grated Parmesan and eat the rest?
A: No, unlike whole cheese where you can cut off the moldy part, if grated Parmesan shows mold, the entire container should be discarded to ensure safety.

Q: How should I store grated Parmesan to extend its shelf life?
A: Store grated Parmesan in an airtight container or tightly sealed original packaging in the refrigerator, away from moisture and heat.

Q: Can freezing extend the shelf life of grated Parmesan cheese?
A: Yes, freezing can extend its shelf life, but it may affect texture and flavor. It’s best used in cooked dishes if frozen and thawed.

A close-up photograph of a bowl of pasta

Leave a Comment