The issue of storing coffee in the freezer vs. room temp vs. fridge, in airtight storage vs non-airtight storage, and whole bean vs. ground is one of the most popular flame wars in the coffee community. And it repeats over and over and over.
All I can tell you is what I do. And the reason I do it is based on being trained as a chemist, reading the scanty scientific literature on this, reading the extensive experiments and reports of other home coffee roasters and most importantly, conducting my own series of experiments to examine the hypothesis of the best way to store coffee to my taste. I have done experiments looking at the permutations of storing coffee in the freezer, fridge and room temp, airtight vs. non-airtight, whole bean vs. ground, vacuum storage vs. ambient pressure, and the kitchen freezer vs. the garage freezer (which is about 20 degrees colder).
First, my opinion on the absolute worst way to store coffee is already ground, in a non-airtight container, in the refrigerator.
Now, my opinion on how I store coffee. I roast coffee every two weeks. As soon as the beans cool, I pour them into a one-liter glass airtight jar that seals with a wire clamp and rubber gasket. The whole beans immediately go into the freezer. They sit there in the airtight frozen dark until use. When I brew some coffee, I take the jar out of the freezer and measure the beans into the grinder. I immediately reseal and return the jar to the freezer. The jar is out of the freezer for less than a minute and is open approximately 20-30 seconds while I measure the coffee out: two scoops for a triple shot of espresso, four scoops for a one-liter french press, and six scoops for the 50 ounce drip brewer. The scoop used is 1/8 cup. I used to measure by weight, but after measuring volumes to get the weights consistently, now use volume. The beans are immediately ground and are usually still frozen or at least very cold when the hot water hits them.
When the jars are empty, I run them through the dishwasher before using them again. The glass jars are not porous, block out odors and flavors, do not absorb odors and flavors and are cleaned before reuse.
So I do not experience issues with moisture condensing on the beans; the beans absorbing odors, flavors or moisture; exposure of the beans to light or repeated temperature shocks to the beans.
Based on the taste tests of my wife and I, coffee stored this way for up to two weeks is indistinguishable from fresh-roasted, bearing in mind that fresh-roasted coffee needs to rest for 24-48 hours to fully develop its flavor. Other experimenters have reported successful storage of up to one month using this method.
Bear in mind that taste is very subjective, and what works for me may not work for you, in terms of a taste difference.
But I am pretty comfortable with my approach, and until I see something in the literature or on the coffee-roasting websites that provides new information, will keep on doing it this way.
