Does grated Parmesan cheese need to be refrigerated?

Quick answer

Grated Parmesan cheese does not need to be refrigerated if it is going to be used within a few weeks. However, for long-term storage, it is best to keep grated Parmesan cheese in the refrigerator or freezer to maintain freshness and prevent mold growth.

Does freshly grated Parmesan cheese need refrigeration?

Freshly grated Parmesan cheese does not require refrigeration if it will be used up quickly. The large surface area exposed during grating makes grated Parmesan more prone to drying out. As such, it is best to use freshly grated Parmesan within 1-2 weeks. Keeping it in an airtight container at room temperature is fine for short-term storage.

Does pre-grated Parmesan cheese require refrigeration?

Pre-grated Parmesan that you buy at the grocery store contains anti-caking agents to prevent clumping. These preservatives allow it to be shelf-stable for months without refrigeration prior to opening. However, once opened, pre-grated Parmesan should be kept refrigerated to maintain quality. The grated pieces have a large surface area exposed to air, which can accelerate moisture loss and mold growth at room temperature.

How to store grated Parmesan cheese

Here are some tips for proper storage of grated Parmesan cheese:

Short-term storage

– Keep grated Parmesan in an airtight container at room temperature for up to 1-2 weeks. Make sure there is no air space in the container to minimize moisture loss. Glass or plastic containers with tight-fitting lids work best.

– You can also store it in the refrigerator for 3-4 weeks. The cold temperature will slow down moisture loss and mold growth.

Long-term storage

– For storage longer than 1 month, keep grated Parmesan cheese in the freezer. It will keep for 4-6 months in the freezer without significant quality loss.

– Place grated cheese in air-tight freezer bags or airtight containers, pressing out excess air before sealing. This prevents freezer burn.

– Hard cheeses like Parmesan do not require thawing before use. You can remove a small amount of frozen grated cheese as needed.

What to avoid

– Do not store grated Parmesan in paper or plastic bags long-term. This will cause fast moisture loss.

– Avoid keeping grated cheese at room temperature for more than 2 weeks. Mold growth and drying out will happen quickly.

Signs Parmesan cheese has gone bad

Here are some signs that indicate your grated Parmesan cheese has spoiled and should be discarded:

– Powdery or crumbly texture – Good Parmesan should feel slightly firm and gritty between your fingers. Soft or crumbly texture means the cheese has dried out.

– Dark or yellow spots – This indicates mold growth, which can happen when stored improperly. Discard moldy areas.

– Sour smell – Grated Parmesan should have a savory, nutty, and salty aroma. An unpleasant sour or pungent odor is a clear giveaway that it has gone bad.

– Unpleasant flavor – Rancid or bitter taste, instead of its usual savory umami flavor.

– Blue, black, or green fuzzy growth – Presence of heavy mold is a sign of spoilage.

– Dry, hard texture – Extreme dryness also means the Parmesan is past its prime.

– Liquid pooling in container – Sign of moisture loss if you see liquid in the package.

Does refrigeration extend the shelf life of grated Parmesan?

Yes, refrigerating grated Parmesan cheese helps extend its shelf life compared to keeping it at room temperature. Here’s how:

Slows down mold growth

The cool temperatures of the refrigerator slow down mold growth. Mold spores need warmer conditions to proliferate. Keeping grated cheese refrigerated will buy you more time before visible mold appears.

Retains moisture better

Refrigeration also helps retain moisture in the grated cheese. The cold air prevents moisture from evaporating too quickly from the large surface area of the grated pieces. Lower moisture loss equals longer shelf life.

Minimizes risk of bacteria

While Parmesan itself is low risk for bacterial contamination, storing it at a cold temperature minimizes the chances of harmful bacteria multiplying to dangerous levels. This is especially important once the package is opened.

Prevents drying out

The closed environment of the refrigerator retains moisture in the cheese to prevent it from drying out prematurely. Keeping grated Parmesan too long at room temperature will cause the pieces to harden and go stale quickly.

Maintains flavor longer

Finally, the cold prolongs the flavor of the cheese. It prevents the oils and aroma compounds from breaking down too fast. Refrigeration will ensure grated Parmesan keeps its signature punchy, savory taste for longer.

How long does grated Parmesan last in the fridge?

Properly stored in the refrigerator, grated Parmesan will last:

– 3 to 4 weeks past the printed sell-by or use-by date on pre-grated Parmesan.

– 1 to 2 months for freshly grated Parmesan stored in an airtight container.

Make sure to check the cheese frequently past the 2-week mark for signs of mold or drying out. Some find keeping the Parmesan container on the bottom shelf of the fridge makes it last longer before going bad.

Does Parmesan cheese need to be refrigerated after opening?

Yes, you should refrigerate Parmesan cheese after opening. An unopened wedge of Parmesan has a long shelf life at room temperature because of its hard texture and low moisture content. However, once exposed to air, the cheese will start to dry out and risk mold growth.

Refrigerating an opened block of Parmesan will keep it fresher for longer in these ways:

– Slows down moisture loss from the cut areas

– Minimizes mold growth

– Prevents the cheese from drying out and becoming crumbly

– Maintains the signature flavor and aroma

Properly stored, an opened block of Parmesan will stay fresh in the fridge for 5-6 weeks. Make sure to rewrap it tightly in plastic wrap or parchment paper before refrigerating. Also, check frequently for any mold development, especially along the cut sides. Discard Parmesan at the first signs of mold.

How to freeze shredded Parmesan cheese

Follow these steps for freezing grated Parmesan cheese:

Use fresh cheese

Grate or shred a fresh block of Parmesan. Freeze grated cheese within 1-2 days of grating for best flavor and texture.

Spread out on a sheet

Lay the shredded Parmesan in a single layer on a parchment-lined baking sheet. Avoid clumping.

Freeze first

Place the baking sheet in the freezer for 1-2 hours. Once frozen solid, transfer to airtight bags or containers.

Exclude air

Pack shredded cheese tightly into freezer bags or containers, squeezing out excess air before sealing.

Freeze for up to 4 months

Store frozen grated Parmesan for up to 4 months at 0°F or below.

Keep frozen until use

Keep the shredded cheese frozen until ready to use. Grate off only what you need.

Can you freeze Parmesan cheese?

Yes, you can freeze Parmesan cheese for long-term storage. Hard cheeses like Parmesan freeze well compared to softer cheeses. Here are some tips for freezing Parmesan:

-Freeze cheese shortly after purchasing for maximum freshness.

-Cut the wedge into smaller portions prior to freezing if you won’t use it all at once.

-Wrap tightly in plastic wrap to prevent freezer burn. Place in freezer bags for double protection.

-Frozen Parmesan lasts up to 6 months stored at 0°F.

-Thaw in the refrigerator overnight before use.

-Let sit 30 mins at room temp after thawing before grating or consuming.

-Pre-grated or shredded Parmesan will not freeze as well. It’s best to grate from a block as needed.

-Avoid repeated freeze-thaw cycles as this can degrade texture.

-Look for ice crystals, dried edges, or odd texture as signs if it has been frozen too long before use.


Grated Parmesan has a shorter shelf life than cheese wedges due to the increased surface area exposed to air. For short term-use, freshly grated Parmesan can be kept in an airtight container at room temperature for 1-2 weeks. Pre-grated Parmesan will last a few months past its ‘best by’ date when unopened.

Once opened, it is best to refrigerate both freshly grated and pre-grated Parmesan. Properly stored in the fridge, grated Parmesan will stay fresh for 3-4 weeks from the use-by date or 1-2 months if freshly grated. Freezing is ideal for longer storage. Frozen grated Parmesan keeps for 4-6 months.

Hard Parmesan wedges also need refrigeration after opening. Well wrapped, Parmesan will last for 5-6 weeks in the fridge. Freezing ungrated wedges also extends shelf life significantly. Following proper storage methods allows you to keep Parmesan cheese fresh for a long time and prevent food waste.

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