KUALA LUMPUR, Sept 21 — I’m ordering a long black at Nozy Coffee in Sangenjaya when I hear a familiar cracking sound. Turning around, I spot a small roaster hidden in the back of the Japanese café.
With a serious look on his face, a young coffee roaster goes about his business of turning raw, green coffee beans into the aromatic, brown beans we recognise.
Which made me wonder, how hard could roasting coffee be?
The pea (berry) and the elephant (bean)
Before roasting can take place, the green beans have to be sorted by size and grade. Here, bad or flawed beans (with defects such as fungus or insect damage) are removed.
Whether sorting is done by machine or hand, this step is essential to ensure a consistent roasting profile (and flavour notes of the resultant cup).
This allows room for surprises to occur. Even in the coffee world, there is a David vs. Goliath battle brewing.
Sometimes you find beans are much smaller or much larger than normal that aren’t necessarily a bad thing, and in fact, in some cases, desired.
Occasionally, the coffee plant would produce a single coffee bean, rather than the standard pair. This small, round bean is called a peaberry (or caracol in Spanish).
Some coffee aficionados believe that because the nutrition that would have gone into two beans ends up in only one, a peaberry is a higher grade of coffee.
Certainly coffee made from peaberry beans tastes different from coffee made from regular beans of the same crop. Also, being smaller in size and rounder in shape, peaberry beans lend themselves to more uniform roasting.
On the other end of the spectrum is the “elephant bean” or Maragogype (so named because it was initially discovered near the Brazilian town of Maragogipe).
A natural mutation of the Typica coffee varietal, it is an extremely large bean with porous qualities that takes on the flavours of the soil its parent tree is planted in.
Peaberry coffee possesses a brighter acidity whereas cups made from Maragogype beans tend to be lighter and less acidic. Roasters have to take this into consideration, in addition to the bean’s size, when roasting.
A crackin’ good time!
Most coffee roasters use roasting machines as these can keep a more consistent temperature, usually about 240–275°C. Other roasters opt to do it by hand, which requires considerably more skill to prevent uneven roasting.
In either case, the beans must be kept moving throughout the process to avoid burning. When the beans hit an internal temperature of about 210°C, the beans will emit a cracking sound. This means the moisture inside has heated enough to steam, snapping the bean’s shell and resulting in what is called the first crack.
The second crack begins at around 235°C, when the caffeol or coffee oils are released from inside the beans. This process is where the real flavour and aroma of the coffee we drink is developed. After the beans are removed from roasting, they are cooled immediately before being packaged.
Coffee roasting is a science of constantly measuring the temperature and other variables, but amateur or home roasters aren’t excluded from the fun, provided they can get hold of some green coffee beans. Just watch out – roast the beans for too long, you might just end up with charcoal!
This story was first published in Crave in the print edition of The Malay Mail on September 20, 2013.