Unopened shredded Parmesan cheese can generally be kept in the refrigerator for an extended period, thanks to its low moisture content. The best practice is to check the expiration date printed on the packaging, as this will provide a good indication of how long the cheese will remain fresh and safe to consume while unopened.
Typically, unopened shredded Parmesan cheese can last anywhere from several weeks to a few months past the printed expiration date when properly stored in the refrigerator at the recommended temperature, which is usually around 34°F to 38°F (1°C to 3°C).
To ensure the cheese stays fresh for as long as possible:
Keep it in its original packaging or transfer it to an airtight container to prevent exposure to air and moisture.
Store it in the coldest part of your refrigerator, like the cheese drawer or the back of the main compartment.
Avoid cross-contamination by keeping the cheese away from other strong-smelling foods.
Once you open the package, the shelf life of shredded Parmesan cheese will be shorter, usually around 1 to 2 weeks. Again, make sure to reseal the package tightly or transfer the remaining cheese to an airtight container after each use.
Always use your senses to check if the cheese is still good to eat. If it develops an off smell, strange appearance, or mold, it's best to discard it. The presence of mold is particularly important to watch out for, as mold on soft cheeses like shredded Parmesan can spread quickly and may not be safe to consume.