Ground coffee does not go bad in the sense that it becomes unsafe to consume, but it does lose its freshness and flavor over time. This is because ground coffee has more surface area exposed to air and moisture, which can cause oxidation and degradation of the coffee compounds. The shelf life of ground coffee depends on how it is stored and packaged, but generally, it can last up to a month in an airtight container in a cool, dry, and dark place. However, for optimal taste and aroma, it is advised to use ground coffee within two weeks of opening the package.