After the coffee has been brewed, you should serve it immediately. If any is left over, store it in a thermos bottle - not on a burner or hotplate. We do not recommend storing coffee in the refrigerator, nor the freezer. We suggest that coffee be kept in an airtight container and stored in a cool, dark, dry place. Putting beans in the refrigerator is not good, even if you use an airtight container.
Refrigerators tend to be both damp and full of odors.
Freezing is better, but only if the container is impeccably airtight, and the freezer topnotch. Dark-roast coffees do not freeze well. The volatile substances have been driven closer to the surface of the bean and when frozen, they congeal and do not reconstitute. However, if you do not have a grinder, and if the ground coffee is not to be brewed for a week or more, and if the container is airtight, then freezing the ground coffee is, in our opinion, the last ditch option. Roasted whole coffee beans keep for a week before they should be consumed.