Parmesan
The answer
Opened parmesan lasts 3–4 weeks in the fridge and about 6 months in the freezer.
Caution On hard cheese, cut mold away — remove at least 1 inch around and below the spot, keeping the knife out of the mold.
How long it keeps
Fridge (40°F) 3–4 weeks (opened) safe window
Freezer (0°F) 6 months best quality
Room temp 2 hours max then discard
Discard Discard soft, shredded, or sliced forms at the first sign of mold.
The answer
Unopened parmesan lasts about 6 months in the fridge.
How long it keeps
Fridge (40°F) 6 months (unopened) safe window
Freezer (0°F) 6 months best quality
Room temp 2 hours max then discard
Discard Discard if moldy, ammonia-smelling, or slimy.
By state & packaging
State Fridge Freezer
Opened block 3–4 weeks 6 months
Unopened 6 months 6 months
Shredded, opened 1 month 3 months
Signs it has gone bad
✕ Mold on shredded or sliced
✕ Ammonia smell
✕ Slimy or greasy surface
FAQ
Can I cut mold off parmesan?
Yes on a firm block — cut at least 1 inch around and below the mold. Discard shredded, sliced, or crumbled cheese at the first mold spot.