Want to make a better cup of coffee? It all starts with freshness.
Just like wine, coffee begins to lose its flavor as soon as it's exposed to oxygen. In the coffee biz we call this the "rule of 15" because everything has a shelf life: green (or raw) coffee beans last 15 months, roasted beans last 15 days, ground coffee lasts 15 minutes, and brewed coffee lasts 15 seconds. After that, the flavor begins to degrade.
For the freshest, most flavorful coffee, always buy recently roasted whole beans and grind them right before you brew. If that's not possible, just remember not to buy too much at once. Keep your coffee in a sealed bag or container in a cupboard, away from extreme heat or cold. And whatever you do, never store it in the freezer, as it will absorb moisture and other flavors.