Yes, coffee has enemies! Actually your coffee begins it’s degradation process as it leaves the roaster. As previously mentioned coffee will lose 50% of it’s more volatile aromatics within the first five days after roasting. Volatile aromatics equate to flavor and the loss is easily identified by cupping the coffees in a sequential manner as they age.Some of the most important degradative enemies of coffee are oxidative reduction, hydrolysis, application of heat and exposure to ultraviolet radiation.
As coffees are exposed to oxygen they undergo a process that results in rancidity, this is most easily identified in coffees in grocery stores, variety stores and small volume coffee shops with low turn over. Oxidative rancidity presents as a sweetly pungent aroma that is definitely not present in freshly roasted coffees and takes 8-10 days if coffees are in whole bean form. This will not make you sick as would be the concern if this occurred in your meat or eggs, however it does signal a substantial loss in quality.
Coffees which have experienced oxidation will be remarkably muted in flavor when compared to it’s fresh counterpart, in fact it may be difficult to even identify it’s true origin at this point. This information is provided to help you be a better consumer .I would never buy a coffee from a coffee shop chain,grocery store,variety store. Never,ever would I buy coffees out of bins or these large bell jars that are so popular as displays.