Coffees that are held for too long run the risk of this taint. Essentially the coffee comes to absorb the flavors of whatever it is stored in – usually the burlap or jute bag. Many times a darker roast on these coffees will conceal this taint. Baggy flavors are the result of several factors: the fats in the coffee absorbing the smell of burlap, the loss in moisture content as the coffee ages, and other chemical changes. For some origins theses changes in flavor can emerge in 1 year, 9 months, even 6 months for some decafs.