The three basic components that affect the flavor of coffee are body, taste, and aroma. Body and taste are relatively stable components since they do not change much over time. Aroma, however, is referred to as a volatile component since it dissipates quickly after roasting.
Of the 1000 or so chemical compounds that make up the flavor of coffee, volatile aroma constituents account for almost 80%. Also present in the roasted bean is a considerable amount of carbon dioxide (CO2), which fills the bean as it swells during the roasting process. Although CO2 does not translate to any specific flavor component there is a correlation between the dissipation of CO2 and the loss of aromatic volatiles. As CO2 leaves the coffee bean, taking aromas along with it, oxygen enters in to fill the empty space.The oxygen reacts with the oils in the bean, turning them rancid.
Why? Simply stated, together CO2 and aromatic volatiles can be referred to as gasses.The gasses are the smell of coffee.When the gasses go away, the flavor goes with it. Once these gasses dissipate, the oils become susceptible to oxygen, creating a rancid flavor.Thus completing the definition of staling: the loss and alteration of flavor.
How can you prevent your coffee from staling? Gasses expand at higher temperatures and contract at lower temperatures. Lowering the temperature of these gasses slows their rate of dissipation. Studies show that for every decrease in temperature of 10 ̊ Celsius, the life of the coffee increases by 50%. Most home freezers are capable of temperatures of -10 to 0 ̊ Fahrenheit, sufficient enough to store coffee beans for several months without degradation.
Freezing is one practice that sets Kaladi apart from other roasters.We place our beans in the freezer directly after roasting so the staling process does not begin before you, the customer, purchase our coffee.
The graph on the next page depicts the staling rate of roaster fresh coffee. Other variables affecting coffee freshness not depicted on this graph are the particular blend, the degree of roast, the addition of moisture, the humidity of the storage area, the rate of circulation, and the altitude, etc.