| "Staling is defined
as the loss and alteration in composition of the volatile aroma constituents"
(Sivetz, Coffee Technology 1979)
There are three basic components affecting the flavor
of coffee, they 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.
What?
To put it simply, together CO2 and aromatic volatiles can be referred
to as gasses. The gasses are the smell of coffee.And 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 I prevent my 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 degrees celsius,
the life of the coffee increases by 50%. Most home freezers are capable
of temperatures of -10 to 0 degrees fahrenheit, sufficient enough to store
coffee beans for several months without degredation.
Kaladi Brothers "ain't like the others!"
Freezing is one practice that sets Kaladi Brothers Coffee apart from other
roasting companies. 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 below 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, the altitude, etc.
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