Without question, coffee is best when used within days of being roasted. Buying from a local roaster (or roasting your own) is the surest way to get the absolute freshest beans. Be wary of buying bulk coffee from supermarket display bins. Oxygen and bright light are the worst flavor busters for roasted beans, so unless the store is conscientious about selling fresh coffee, the storage tubes get coated with coffee oils, which turn rancid. Coffee beans packaged by quality-conscious roasters and sold in sturdy, vacuum-sealed bags are often a better bet.
Always store opened coffee beans in an airtight container. Glass canning jars or ceramic storage crocks with rubber-gasket seals are good choices. Never refrigerate (roasted beans are porous and readily take up moisture and food odors). Flavor experts strongly advise against ever freezing coffee, especially dark roasts. Optimally, buy a 5- to 7-day supply of fresh beans at a time and keep at room temperature.
Snobbism among coffee drinkers can rival that of wine drinkers, but the fact is that an astonishing world of coffee tastes awaits anyone willing to venture beyond mass-marketed commercial brands. Specialty coffees that clearly state the country, region or estate of origin can provide a lifetime of tasting experiences. By all means look for 100% pure Arabica beans. The cheap alternatives may contain Robusta beans, noted for their higher caffeine content but harsh flavors. “Nasty” is a term commonly linked to Robusta coffees by Arabica devotees.