Which cheese does not have to be refrigerated?

Here's why:

* Low Moisture Content: Parmesan cheese is hard and has a very low moisture content, making it difficult for bacteria to grow.

* Salting and Aging: It's heavily salted and aged for a long time, which further inhibits bacterial growth.

However, it's important to note that:

* Once opened: Parmesan cheese should be stored in an airtight container in a cool, dry place.

* Not all "Parmesan" is the same: Be sure to check the label for "Parmigiano Reggiano," the true, authentic Parmesan cheese from Italy.

Let me know if you have any other questions about cheese!