Parmesan cheese, known for its hard texture and nutty, savory flavor, is a popular cheese used in many dishes. Like most cheeses, Parmesan has a stamped expiration date printed on the rind or packaging to indicate how long it will remain at peak quality. However, if stored properly, Parmesan may still be safe to eat and retain good flavor even past its printed date. Here’s what you need to know about using Parmesan cheese after the expiration date.
Why does Parmesan cheese have an expiration date?
All packaged foods, including Parmesan cheese, have expiration dates to provide consumers with an idea of how long the product will remain at peak quality and follow food safety guidelines. For Parmesan, the expiration date tells you when the cheese maker believes the cheese will start to deteriorate in quality and no longer taste its best.
However, the expiration date does not indicate when the cheese will become unsafe to eat. Parmesan is a hard, low-moisture cheese made from cooked and aged cheese curds. When properly stored, it has a relatively long shelf life due to its low moisture content and aging process. The printed expiration date is simply the manufacturer’s recommendation for best flavor.
How long does Parmesan cheese last after opening?
An unopened wedge or block of Parmesan will typically stay fresh in the refrigerator for about 6-8 months past the printed expiration date. However, once opened, Parmesan should be used within 4-6 weeks for best quality.
When exposed to air, Parmesan can dry out and start to form mold. Storing the cheese in an airtight container helps prevent drying out. You can also wrap the cheese tightly in plastic wrap or parchment paper before placing it in a container. Proper storage can extend the shelf life for months past the printed date.
How to tell if Parmesan cheese has gone bad
There are a few clear signs that indicate your Parmesan cheese is past its prime or potentially unsafe to eat:
- Mold growth – dry, fuzzy white or blue-green mold
- Significant drying around the edges and sides
- Watery spots or pockets
- Soft, wet, or sticky texture (should be hard and crumbly)
- White film on the surface
- Yellow, brown, or orange discoloration
- Ammonia or sour odor
- Very strong, unpleasant smells
- Bitter, acidic, or unpleasant flavors
- Lacks typical nutty, savory Parmesan flavor
If your Parmesan exhibits any of these signs, it’s best to discard it. Don’t eat cheese with mold, an off smell, or odd texture, as it could make you sick.
Is it safe to eat Parmesan cheese after the expiration date?
Most of the time, it’s completely safe to use Parmesan past its printed date, provided it was properly stored and there are no signs of spoilage. Hard cheeses like Parmesan tend to have a very long shelf life. When kept continuously refrigerated, Parmesan can maintain both its safety and quality for months or even years after the sell-by or best-by date.
Here are some general guidelines for Parmesan shelf life when refrigerated:
- Unopened Parmesan block – safe for 6 to 8 months past printed date.
- Opened Parmesan wedge – safe for 3 to 4 weeks past printed date.
- Grated Parmesan in sealed packet – safe for 3 to 4 months past printed date.
Keep in mind that the shelf life varies based on how well the cheese was stored. Parmesan that stays fresh in the fridge much longer than the guidelines could still be safe to eat as long as there are no signs of spoilage.
How to store Parmesan cheese
To get the longest shelf life out of your Parmesan wedge or block after opening, proper storage is key. Here are some tips for storing Parmesan cheese:
- Keep Parmesan tightly wrapped in plastic wrap or waxed paper. All surfaces should be covered. This prevents drying out.
- Place the wrapped cheese in an airtight container or bag. Glass or hard plastic containers work best.
- Store in the refrigerator set to 40°F or below. Consistent cool temperature is important.
- Keep Parmesan away from high-moisture foods like produce that could cause early mold growth.
- Avoid freezing Parmesan for long-term storage as this can cause texture changes.
How to use Parmesan cheese after the expiration date
Using Parmesan in cooking applications can extend its shelf life even further past the printed date. The heat from cooking kills any harmful bacteria that could be present. Here are some great ways to use up Parmesan cheese after it expires:
- Add to sauces, soups, casseroles, pasta dishes
- Top homemade pizza before baking
- Mix into risotto or polenta
- Coat vegetables before roasting
- Stir into egg dishes like frittatas or omelets
- Bread and fry for Parmesan crisps
- Fold into biscuit, scone, or bread dough
- Sprinkle over gratin dishes or pasta bakes
- Mix into quick breads and muffins
- Fold into pie dough
- Knead into pizza dough
General Cooking Tips
- Grate or shave expired Parmesan to freshen it up
- Combine with breadcrumbs, herbs, lemon zest, etc. for seasoning blends
- Add to compound butters
- Use in place of fresh Parmesan in any recipe
With its intense umami flavor, Parmesan cheese adds a savory boost to both sweet and savory applications. Unless mold is present, incorporating expired Parmesan into cooked recipes is perfectly safe.
What’s the white stuff on Parmesan cheese?
It’s common to see white specks or powdery white areas on the rind of Parmesan cheese. This white residue is completely natural and harmless – it’s simply crystals formed by the amino acids tyrosine and calcium lactate in the cheese.
Tyrosine crystals can form when amino acids accumulate on the surface during the aging and crystallization process. The calcium lactate crystals (also called “cheese crystals”) occur when excess calcium separates from the cheese proteins during ripening.
Neither tyrosine nor calcium lactate crystals affect the flavor or safety of Parmesan cheese. The growth of these harmless white specks is normal in aged hard cheeses like Parmesan.
Can you freeze Parmesan cheese?
It’s possible to freeze Parmesan cheese for long-term storage, but you may notice some minor texture and flavor changes after thawing. Freezing makes Parmesan crumbly and impart a grainy mouthfeel.
For best results, grate or shave Parmesan before freezing so it’s ready to use from frozen. Wrap tightly in plastic wrap and foil and freeze for 3 to 6 months. Thaw in the refrigerator before using.
While not ideal, freezing can extend the shelf life of Parmesan by several months. It also makes the cheese more prone to absorbing refrigerator odors, so wrap it tightly.
With proper storage in the refrigerator, Parmesan cheese can often be safely consumed and provide good flavor quality long after its printed expiration date. Signs of mold, foul odors, or textural changes mean it’s time to discard your Parmesan. But the typical “sell by” or “best by” dates are simply guidelines for peak freshness rather than safety.
Because of its low moisture and high acidity from the aging process, Parmesan has a naturally long shelf life. Keep your wedge or block of Parmesan well wrapped and contained in the fridge and it will last for many months past the date on the package.
Cooking expired Parmesan also allows you to safely take advantage of its rich, savory umami flavor to boost the taste of soups, sauces, baked goods, and more. With proper storage and handling, Parmesan cheese can be an extremely shelf-stable item in your fridge or pantry.