Refrigerated or frozen coffee can dehydrate the coffee reducing the moisture content of the product.
Buy whole beans. Would you bake fresh bread and cut it in to pieces to lie out and dry for days ahead of serving it? Of course not! The same goes for coffee. For the best tasting coffee, buy your beans whole and store them in a sealed container in a dark place. Grind them and use within 15 minutes for the maximum flavor. Air and light is coffee's worst enemy. Coffee picks up other flavors, so be careful where it is stored.
How finely the coffee is ground, the coffee to water ratio, the temperature of the water and how quickly the water "seeps" through the coffee determines the quality of the cup.