While this might be the case, buying locally roasted beans will reward you with a better tasting coffee, and it all comes down to freshness. Coffee has a long shelf life in terms of spoilage, but for peak aroma and taste you have one to two weeks after roasting before a decline begins, even if you buy whole beans. If you're buying coffee at the supermarket, this freshness window will likely have already passed by the time it arrives on shelves.