degrees
of roast
One
of the more confusing areas for newcomers to specialty coffee has
to do with roast names. Terms like "city", "full
city", "French", "Espresso" and so on refer
to radically different roast colors, depending on the roaster and
region. Moreover, some roast names are also blend names; "Espresso,"
for example often refers to a particular degree of roast for a blend
of coffees created for use in an espresso brewer. Even when the
colors appear to be the same, the coffees may have entirely different
flavors. The types of beans selected, how and when heat was applied,
and the length of time in the roaster are invisible but critical
factors in creating the ultimate flavor of the beans.
For simplicity's sake, we have divided
roasts into four broad categories:
| LIGHT:
Lightly-roasted coffees (roughly the color of cinnamon) tend
to have intense aromas, with crisp, lively acidity as the dominant
flavor note and relatively light body. |
 |
MEDIUM: Medium-roasted beans (roughly light-brown in
color) typically are full in body while still maintaining most
of their acidity. |
 |
| DARK:
Dark roasts (dark brown in color with slight traces of oil on
the surface) replace acidity with a slight roasty bitterness
that creates a more pungent flavor. |
 |
| VERY
DARK: Very dark roasts (dark brown to black in color
with oily bean surfaces) have a pronounced carbony bitterness
as their primary flavor with a noticeable decrease in body. |
 |
The
Roasting Process
The roasting process causes a complex series of chemical changes.
Over a period of roughly 18 to 20 minutes, the green coffee loses
moisture, turns yellow, and "pops" open, much like popcorn.
As it does so, the bean nearly doubles in size, and begins to assume
the very light tan color of lightly-roasted coffee. Once this stage
is achieved (about 8 minutes into the roast), the heat source is
turned down, and the coffee rapidly darkens in color. Once the desired
degree of roast for a given coffee has been achieved, the process
is stopped using either a brief spray of water followed by air cooling,
or air alone.
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