To Freeze or Not To Freeze
Often times, it would be suggested to store your coffee in the freezer. After all, at colder temperatures, molecular activity (including flavour molecules migrating) slows down, right? This is true. But does slowing molecular migration down preserve the flavour of the coffee? Not necessarily.
You see, there are other variables at work in a freezer:
~ A frozen environment will allow water molecules to attach to the coffee beans and/or packaging.
~ A freezer has other flavour molecules floating around in it (remember that fish sale 3 weeks ago?)
~ A freezer door opens and closes very often under normal use.
What does this mean for your coffee? This means that water will contact the surface of the bean and ice will form. When the water melts, that water will find its way into the porous bean and will begin to deteriorate the quality of the coffee. Secondly, you should keep in mind that roasted coffee is porous to odours. So if you put your coffee in the freezer, it needs to be well protected against the possibility of tasting like liquid salmon.
Your goal should be to keep the coffee’s contact with water to a minimum. Moreover, the coffee should thaw only once – right before it is brewed. I would suggest keeping the beans in the original packaging. Then place the package in a zippered storage bag. You can draw out the excess air by using a straw to suck out the air while you close the bag. If you do not have a zippered bag, you can wrap the beans using a plastic wrap. After this initial wrapping, I place the coffee bean bundle in another paper bag. Again, wrap the bag with plastic wrap, then I cover it with foil. It may sound like overkill, but it is worth it. You’ve invested money in this gourmet coffee, you need to protect your investment.
Freezing coffee is applicable for storage of coffee that won’t be used within 1-2 weeks of roasting. It is not optimal for everyday use.
If you are wondering about the refrigerator, it is a no-no for coffee. Since the temperature is generally around 4 degrees celcius, the water that is inside doesn’t freeze. It is a cold mist that lingers on the coffee and there are even more scents and flavour molecules floating around. Liquid water is coffee’s worst enemy during storage. Under no circumstance would I ever recommend using the refrigerator for storing coffee.
Storing coffee at room temperature is the most convenient method of storage. It works well for coffee that will be consumed within one to two weeks of purchase.
When storing at room temperature certain environmental factors to be minimized and eliminated if possible.
~ Excessive Heat
~ Direct Sunlight
~ Other flavors
All of these factors will destroy the coffee’s flavour. A great device for mitigating these factors is a ceramic canister that holds ½ lb. to 1lb. of coffee. The canister should have some sort of sealing mechanism that does not allow air to circulate.
Additionally, a ceramic canister will protect the coffee from sunlight, water and flavor migration. Flavour migration happens when the container harbours flavours. Plastic containers are great examples of this concept. Plastics allow flavour molecules to penetrate and metallic canisters allow metallic flavours to migrate. Ceramic containers, on the other hand, are sealed and baked. Consequently, they will not corrupt the flavour of the coffee.
Short-term storage (within one to two weeks of purchase) should be done in a ceramic container with a good sealing mechanism. Fill the canister to capacity.
If you find yourself at a coffee shop that has a sale on your favourite specialty roast and if you buy more than you can brew in a week or two, store the coffee properly.
Determine which portion of that coffee you will consume within one week and put the amount that you can consume in that week into a ceramic canister.
Divide the rest of the coffee into ‘one-week packages’ and store in the freezer as I’ve described in this article.
When you need more coffee, pull another ‘one-week package’ out of the freezer and transfer the coffee into short-term storage.