Should you freeze or just refrigerate your coffee? Store it in jars, paper or plastic bags? Does it matter if it's whole bean coffee or ground coffee? These are the questions asked by most coffee buyers.
Air and light are the biggest enemies of coffee. Coffee will begin to lose its flavor after roasting once exposed to air and light. The more your coffee comes into contact with those two elements the more flavor it loses.
Green beans store the best- Stored in a cool dark location they can last over a year. The problem with green beans is that there is a lot more work involved to turn them into a cup of coffee. You'll have to roast them and then grind them. This may be undesirable for an average coffee drinker.
Roasted Ground Coffee:
This is the most volatile form, and generally looses significant flavor in a few days. Ground coffee has all that extra surface area therefore exposing it to air. If you must use ground store in an air-tight and light-proof container.
Roasted Whole Beans:
Grinding your own beans is pretty simple, and will be worth the effort. Store roasted whole beans at room temperature in an airtight container that blocks the light. Plastic or metal containers may contaminate the taste of your coffee, so try to use ceramic if possible. If you use clear glass, then store in a dark cupboard.
Most experts DO NOT recommend keeping coffee in the freezing.
Why are there little holes or valves in my bag of coffee beans?
Freshly roasted coffee beans give off a great deal of carbon dioxide, for several hours after roasting. To prevent this "off-gassing" from bursting their bags, coffee roasters used to hold coffee for up to 24 hours before packaging. This meant that the coffee was being exposed to air for 24 hours before packaging. By using bags with one-way air valves coffee can be packed immediately allowing the release of the gasses that occur after roasting and not allowing any air to get in. A bag with valves tells you that your supplier is providing you fresh roasted coffee, and that your coffee is as fresh as possible.
The bottom line is that good coffee is fresh coffee!