I work at a coffee roaster. When coffee is ground it lets off gas, so it must sit unpackaged for at least 1-2 days before it gets packed, or it will cause the bags to explode due to pressure. Some coffee packaging has little valves that lets excess pressure out but not air in, so these bags can be packed pretty much immediately after the coffee is ground. For k-cups and the like, I can almost guarantee that the coffee has been exposed to air for at least a little while before it gets put into those pods. Point is, if you grind the beans yourself right before you make your coffee, that's probably the best, but most coffee you buy pre ground will not be the freshest because it has to gas off before it can be packed.