There are popular misconceptions on the way roasted coffee should be stored and maintained. The enemies of roasted coffee are moisture, air, light, and heat. Storing your coffee away from them will keep it fresher longer. Therefore, an airtight container stored in a cool, dry, dark place is the best environment for your coffee.
Freezing Coffee - Not as Good as an Iced Mocha
Some people store their coffee in the freezer thinking it is going to keep the coffee fresh. Here are a couple of reasons why storing coffee in your freezer is a bad idea:
Coffee is porous. This is a good thing for fans of flavored coffee as the beans absorb the coffee flavoring syrups and oils that are used to make flavored coffee. However, if given the chance, coffee can also absorb other things like the flavor of seafood or the moisture that your freezer produces. This moisture will in turn deteriorate the coffee and even make it taste like, well... like a freezer.
When coffee is roasted, the beans release their oils and essences to give the coffee its distinct flavor. You'll notice these oils are more prominent on dark-roasted coffee and espresso. When you break down these oils by freezing, you are removing the flavor.
Think about it...if coffee tasted better and fresher from the freezer, then you would buy it in the frozen food section, your local coffee shop might look more like an ice cream parlor, and our power bills would be through the roof trying to maintain a meat-locker the size of a warehouse.
When to Freeze Coffee
How long does coffee stay fresh? A good rule to use is two weeks. Now, if you happen to have found a great price on bulk coffee, and you don't plan on using it within two weeks, the freezer can be an acceptable one-time shot. What this means is that once you take it out of the freezer, it should never go back in. The constant changes in temperature will wreak havoc on your coffee. The frozen moisture on your coffee will melt and be absorbed into the bean. When you put it back into the freezer, you are repeating the process. The goal in freezing coffee is to keep it away from moisture. If you have a five-pound bag of coffee to store, divide it up into weekly portions. Wrap those portions up using sealable freezer bags and plastic wrap. I've even read you should go so far as to suck out the excess air from the freezer bag using a straw! Remove the weekly portion when you need it, and store it in an air-tight container in a dry place like your pantry. Do not put it back into the freezer!
When to Refrigerate Coffee
Never, unless you are conducting a science experiment on how long it takes to ruin perfectly good coffee. The fridge is one of the absolute worst places to put coffee.
Buy whole beans and keep them whole as long as you can.
Would you cut a cake into pieces the day before you plan to serve it? Would you buy it pre-sliced? Of course not! The pieces would quickly become stale and the frosting would start to dry out. The same goes for coffee. Grinding the coffee breaks up the beans and their oils, exposes the beans to air, and makes the coffee go stale a lot faster, no matter how you store it. This holds especially true for flavored coffees! For the best tasting coffee, buy your beans whole and store them in a sealed container in a dark place. Grind right before serving.
Vacuum-sealed coffee does not equal fresh coffee. When coffee is roasted, it releases carbon dioxide and continues to release it for days afterward. Fresh-roasted coffee can be packaged in valve-sealed bags to allow the gasses to escape and will taste best about 48 hours after roasting. To be vacuum sealed, the coffee has to first release all its CO2 or it will burst the bag. The vacuum bag will indeed help preserve coffee longer while it ships and maybe sits on a store shelf, but before it shipped it had to sit around for a while before it was "sealed for freshness." Vacuum sealing is best for pre-ground coffee, which we already know is not going to taste as good as fresh-ground coffee.
A quick review for serving the best coffee:
Buy whole beans directly from a coffee roaster if possible.
Look for valve-sealed bags, not vacuum-sealed.
Store your coffee beans in a sealed container in a dark place.
Grind your beans just before brewing.