To ensure the best coffee at home, buy whole beans roasted within the past week and grind them just before you brew. It is always best to buy a small amount of coffee at a time. Odd as it may sound, the surest way to obtain recently roasted coffee is to order it by mail, since companies usually ship a day or two after roasting. Air and moisture are the enemies of coffee beans. Virtually all canned coffee is preground, meaning that by the time the buyer opens the can, the coffee is probably on the road to staleness. Even ΓÇ£vacuum-packedΓÇ¥ cans almost always retain a small amount of oxygenΓÇöenough to start turning the coffee stale. A better solution is the valve-lock bag, which has a one-way valve to allow carbon dioxide to escape without letting in oxygen. These give coffee a shelf life of 3 months at the most, but thatΓÇÖs only if the bag remains unopened.
The best way to store coffee beans, ground or whole, is in an opaque, airtight canister just big enough to hold them, with as little air at the top as possible. Keep the coffee at room temperature and use it within 10 days if possible. Many people store coffee in the refrigerator or freezer. The problem is that the beansΓÇöand, even more so, ground coffeeΓÇöcan absorb food odors in the refrigerator. (Bags of ground coffee are so absorbent, in fact, that they were once recommended as refrigerator refreshenersΓÇöthe precursor to baking soda.) The freezer is a better option, though ground coffee can absorb odors even thereΓÇöand the oils in beans congeal when frozen, possibly affecting the body of the brewed coffee.
