Yes. Parmesan cheese lasts 3–4 weeks in the fridge and 6 months in the freezer. After that, or sooner if stored badly, it spoils: watch for the signs below.
How to tell if parmesan cheese is bad
Smell
Ammonia or a sharp sour smell beyond the cheese's usual aroma.
Texture
Slimy surface, or very dry and cracked all the way through.
Colour
Darkened or yellowed edges, or new colours that are not part of the cheese.
Mould
On hard cheese, cut 1 inch around the spot. On soft or shredded cheese, discard.
Parmesan cheese past the expiration date
Unopened
FoodKeeper gives unopened parmesan cheese 6 months in the fridge, counted from the day you buy it. "Best-by" and "sell-by" describe quality and stock rotation, not safety; only infant formula carries a federally required use-by date.
Opened
Once opened, the printed date no longer applies. Count 3–4 weeks in the fridge from the day you open it.
How to keep parmesan cheese fresh longer
- Wrap in wax or parchment paper, then loosely in plastic, so it can breathe.
- Store in the cheese drawer or a lower shelf at 40°F (4°C) or below.
- Use a clean knife each time to avoid introducing mould.
