Parmesan CheeseShelf Life, Storage, and Spoilage Guide
Pantry
Not RecommendedNot recommended
For optimal quality and safety, Parmesan cheese should always be refrigerated once opened or if purchased pre-grated/shredded. Unopened hard blocks may last a very short time at cool room temperature, but refrigeration is always best.
Refrigerator
3-5 days (opened, grated/shredded); 6 weeks (opened, hard block); 2-4 months (unopened, hard block)
Store hard block Parmesan tightly wrapped in plastic wrap, then foil or parchment paper, or in an airtight container to prevent drying and mold. Grated or shredded Parmesan should be kept in its original packaging or an airtight container. Always store in the coldest part of the refrigerator.
Freezer
3-6 months
Parmesan cheese, especially hard blocks or pre-grated, freezes well. Wrap hard blocks tightly in plastic wrap, then foil. Grated Parmesan can be frozen in its original packaging or an airtight freezer-safe bag/container. Freezing may alter texture slightly, making it more crumbly, but it remains safe.
Signs of Spoilage
- Visible mold (especially on grated/shredded or soft parts of block cheese)
- Off-odor (sour, ammonia-like, or unusually strong)
- Slimy or unusually sticky texture
- Significant discoloration beyond normal aging
Room Temperature Safety
The 'Danger Zone' for food is between 40°F (4°C) and 140°F (60°C), where bacteria can multiply rapidly.
If Parmesan cheese has been left out at room temperature for longer than the recommended time, it should be discarded to prevent foodborne illness, even if it looks and smells fine.
Safe Handling
Always keep Parmesan cheese refrigerated at 40°F (4°C) or below.
If mold appears on hard block Parmesan, cut off at least 1 inch around and below the mold spot. Do not use the knife that cut the mold to cut other parts of the cheese. Discard soft, grated, or shredded Parmesan if mold is present.
Prevent cross-contamination by using clean utensils and cutting boards when handling cheese.