How fresh should coffee be?
Generally speaking, fresh coffee is better than old coffee – but that's only part of the truth.
After roasting, coffee contains a lot of CO2, which escapes slowly throughout the following weeks. This is also the reason for the valve on the coffee bag (it's not there so you can smell the coffee): CO2 can leave the bag, which won't inflate, and oxygen won't get into the bag, which prevents a quick oxidation.