How long is feta cheese good for after you open it?

Once opened, feta cheese can last for up to two weeks in the refrigerator. To maximize its shelf life, store it in an airtight container and keep it immersed in its brine or a mixture of water and salt. Feta cheese should not be left out at room temperature for more than two hours. Additionally, it should be discarded if it develops an unpleasant odor or flavor, or if there is any mold growth.