Buying and Storing Coffee
A first decision in drinking coffee is how and where to buy the beans. The decision is complicated by roasted coffee's vulnerability to staling. Freshly roasted coffee is at its best about a day out of the roaster. If it is kept in an airtight container as whole, unground beans, it can remain fresh if ground and brewed in a week to ten days. But by three weeks out of the roaster, if not frozen or preserved in special packaging, even whole bean coffee will spoil.Retailer strategies differ on how to deliver whole beans to consumers economically and as fresh as possible. One way is to roast the coffee and sell it within a week after roasting. Freshly roasted coffee naturally degasses or emits carbon dioxide. This slowly discharging gas protects the beans from penetration by oxygen and consequent staling. When a coffee stays around too long owing to unexpected buying patterns, the store may start brewing it as the "coffee of the day" until its gone.
However, the roast-it-and-move-it strategy demands discipline and a deep commitment to customers. 
Other roasters take a less risky but more expensive route: Immediately after roasting they seal the whole-bean coffee in bags that have been flushed with inert gas to chase out oxygen. Thereafter the carbon dioxide produced by the coffee slowly trickles out a one-way valve, further defending the coffee against staling.
Such gas flushed valve bags are remarkably effective in preserving coffee freshness. Manufacturers of the bags claim that they preserve flavor and aromatics for up to three or more months. In fact, most responsible coffee sellers take no chances and aim at about six to eight weeks. The one problem with such bags: When the coffee first emerges from the bag it tastes roaster-fresh. But thereafter it seems to degrade in flavor a bit more rapidly than freshly-roasted coffee.
The absolutely most responsible approach is pursued by roasters who pack their coffee in valve bags, but date the bags and pull them off the shelves after about three weeks. Simply because coffee is sold as whole beans in bins does not mean it has not seen the inside of a valve-bag, by the way. Many large roasters, Starbucks included, ship their coffee to their stores in five-pound valve bags, which are then opened and dumped into the bins.
Keeping Coffee Fresh Roasted whole coffee beans keep fairly well. The bean itself is a protective package, albeit a fragile one. Stored in a dry, airtight container to prevent contamination or contact with moisture, roasted whole-bean coffee holds its flavor and aroma for about a week. After two weeks, it still tastes reasonably fresh, but the aroma begins to slip; after three the flavor starts to go as well. Whole-bean coffee kept past a month, though still drinkable, will strike the palate as lifeless and dead.
But if the natural packaging of the bean is broken -- that is, if the coffee is ground -- it goes stale in a few hours.Canning coffee is one of the useless gestures typical of convenience foods. Essentially, the natural coffee package, the bean, is broken down and replaced with an inefficient artificial package, the can. Furthermore, canned coffee is not only pre-ground, but pre-staled. Freshly roasted and ground coffee releases carbon dioxide gas. If the coffee were put in the cans fresh, the gas would swell even the strongest can and turn it into an egg-shaped time bomb. Various technological solutions have been found for this problem, but none is conducive to ensuring richly flavored coffee. When consumers break open the artificial package, they may find a coffee that is relatively fresh-but not for long. Since the small natural packages that make up a pound of ground coffee have already been broken, the oxygen that enters the can every time you peel off the plastic lid rapidly completes the job the canning process started.
So the easiest and most effective approach is to break down the beans as close as possible to the moment you want to use them -- in other words, grind your coffee just before you brew it. Grinding coffee fresh takes very little time. Grinders are inexpensive and range from efficient electrics to picturesque replicas of old hand grinders. Grinding coffee fresh is the single best thing that you can do to improve the quality of your coffee.
Storing Coffee:
Roasted coffee beans constitute a natural package for the volatile, delicate oils that supply coffee's aroma and flavor. Storing coffee in whole-bean form and grinding it immediately before brewing is a first and essen
tial step to experiencing it at its peak.
Buy the coffee as whole beans. Put the beans in an airtight container in a cool, dark place, and take out only as much as you want to grind and brew immediately. Airtight means airtight: no recycled coffee cans or cottage cheese cartons with plastic lids. Rather, a solid glass jar with a rubber gasket inside the cap that gives a good seal.
Putting beans in the refrigerator is downright foolish, even if you use an airtight container. Moisture is the enemy of roasted coffee. The flavor "oils" in roasted coffee are not oils, but very delicate, volatile water-soluble substances that moisture immediately dilutes and odors taint. Recall that refrigerators tend to be both moist and full of odors.
Freezing, however, is an excellent way to preserve whole-bean coffee if you do not intend to drink it within a week. Seal the beans in a freezer bag, put the bag in a part of the freezer that does not lose temperature every time you open the door, and remove only as many beans as you intend to consume in a day, returning the rest to the freezer.
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