We managed to find a wonderful Coffee, freshly harvested and roasted, valuable, aromatic and flawless. We have bought it and we are going home. How can we best preserve such a delicacy?
Coffee is by its nature antioxidant, so it tends to react with the oxygen it comes in contact with, taking that terrible, widespread and unpleasant oxidized and rancid smell that everyone has experienced at least once. This oxidation reaction is accelerated by heat (even more by temperature variations) and by light. In addition, Coffee is awfully hygroscopic and therefore tends to absorb moisture, but also other smells extraneous or widespread in the environment.
For best preservation: – try to minimize oxidation. Coffee beans are recommended, to be grinded only at the time of use- try to limit the rate of oxidation reactions by maintaining Coffee at a constant temperature- try to minimize exposition to light for the same reason, therefore store Coffee in the dark- limit the exchange of smell and exposure to oxygen: we suggest to store it in an sealed container.
To sum up: Coffee beans freshly harvested and roasted, stored in an airtight container at constant temperature (15°/18° C) or, even better, in the fridge, from which we will take from time to time ONLY the amount of Coffee that will be used, putting back the rest in a refrigerator at constant temperature.
A few days after roasting, the Coffee will be ready for use: roughly, it will stay “in shape” according to the attention we have paid for maximum 5/6 month, after which it will gain an irretrievable rancid smell.
Why not the freezer? Of course the freezer temperature blocks the oxidation reactions of the Coffee, but once brought back to room temperature it will suffer such an extensive oxidative shock that aging will be extremely accelerated. Not even taking from the freezer only the exact amount required each time is a winning strategy, because the ground at -20° C would radically change the thermal equilibrium of the extraction (a mass at -20° C will cool filter and filter holder) completely distorting the taste-olfactory profile of the preparation, probably making it less enjoyable.