Look for: Ground coffee and coffee beans in tightly sealed, air and
moisture proof containers.
Avoid bulk coffees or coffee beans stored in open bins. When coffee is
exposed to air, the volatile molecules that give it its distinctive flavor
and richness escape, leaving the coffee flavorless and/or bitter.
Store unopened vacuum-packed cans of ground coffee or coffee beans in a
cool, dark cabinet—where they will stay fresh for six months to a year.
They will lose some flavor in storage, though, because it is impossible to
can coffee without trapping some flavor-destroying air inside the can.
Once the can or paper sack has been opened, the coffee or beans should be
sealed as tight as possible and stored in the refrigerator. Tightly
wrapped, refrigerated ground coffee will hold its freshness and flavor for
about a week, whole beans for about three weeks. For longer storage,
freeze the coffee or beans in an air and moisture proof container. (You
can brew coffee directly from frozen ground coffee and you can grind
frozen beans without thawing them.)
If you make your coffee with tap water, let the water run for a while to
add oxygen. Soft water makes "cleaner"-tasting coffee than mineral-rich
hard water. Coffee made with chlorinated water will taste better if you
refrigerate the water overnight in a glass (not plastic) bottle so that
the chlorine evaporates.
Never make coffee with hot tap water or water that has been boiled. Both
lack oxygen, which means that your coffee will taste flat.
Always brew coffee in a scrupulously clean
pot. Each time you make coffee, oils are left on the inside of the pot. If
you don't scrub them off, they will turn rancid and the next pot of coffee
you brew will taste bitter. To clean a coffee pot, wash it with detergent,
rinse it with water in which you have dissolved a few teaspoons of baking
soda, then rinse one more time with boiling water.