Unpasteurized cheese, also known as raw-milk cheese, is made from milk that has not been pasteurized. Pasteurization occurs during cheesemaking when milk is heated at the beginning of the cheesemaking process to destroy microorganisims that can potentially cause sickness or spoilage.
Being stored in brine, Halloumi is quite a salty cheese; if it is too salty for you, simply rinse it under running water before using it. Once opened, Halloumi can be kept in fresh water in the fridge for several days, or it can be frozen for up to 3 months.
The precise answer depends to a large extent on storage conditions - to maximize the shelf life of opened sour cream, keep it refrigerated at all times. To maximize the shelf life of sour cream after opening, keep refrigerated and tightly covered, either in the original packaging or in an airtight container. Properly stored, an opened package of sour cream will generally last for about two weeks after opening, assuming it has been continuously refrigerated.