Dairy
Hard block or grated/shredded (fresh or shelf-stable)

Parmesan CheeseShelf Life, Storage, and Spoilage Guide

Sourced from
USDA FoodSafety.govFDA

Pantry

Not Recommended

Unsafe for opened block or fresh grated; Unopened shelf-stable grated: until 'Best by' date

Opened block or fresh grated Parmesan should always be refrigerated. Unopened shelf-stable grated Parmesan can be stored in a cool, dry pantry until its 'Best by' date. Once opened, shelf-stable grated Parmesan should also be refrigerated.

Refrigerator

Opened package: 3-4 weeks; Unopened package: 6 months

Store tightly wrapped in plastic wrap or aluminum foil, or in an airtight container, to prevent drying out and absorption of odors. Store in the coldest part of the refrigerator.

Freezer

6 months

For best quality, freeze in small portions. Wrap tightly in plastic wrap, then in aluminum foil, or place in heavy-duty freezer bags. Freezing may alter texture, making it more crumbly, but it remains safe.

Signs of Spoilage

  • Visible mold (other than intentional mold on certain cheeses)
  • Off-odor, such as a sour or ammonia smell
  • Slimy or unusually soft texture
  • Significant discoloration beyond normal aging

Room Temperature Safety

The 2-hour rule: Perishable foods, including cheese, should not be left at room temperature for more than 2 hours. If the ambient temperature is above 90°F (32°C), the limit is 1 hour.

The 'Danger Zone' for bacterial growth is between 40°F (4°C) and 140°F (60°C).

Promptly refrigerate or discard Parmesan cheese that has been left out at room temperature for too long. Do not taste food to determine its safety.

Expert Tips

Safe Handling

1

Always wash hands before and after handling cheese.

2

Keep cheese refrigerated at 40°F (4°C) or below.

3

If mold appears on hard Parmesan cheese, cut off at least 1 inch around and below the mold spot. Do not use the moldy part. Discard soft, shredded, or crumbled cheese with mold.

4

Avoid cross-contamination by using clean utensils and cutting boards.

Related Items

Comparisons

Cheddar Cheese (hard)
Pantry
Unsafe for opened product; Unopened shelf-stable: until 'Best by' date
Fridge
Opened package: 3-4 weeks; Unopened package: 6 months
Freezer
6 months
Swiss Cheese (hard)
Pantry
Unsafe for opened product; Unopened shelf-stable: until 'Best by' date
Fridge
Opened package: 3-4 weeks; Unopened package: 6 months
Freezer
6 months
Cream Cheese (soft)
Pantry
Unsafe
Fridge
Opened package: 1-2 weeks; Unopened package: 2 weeks
Freezer
Not recommended