From the Seed to the Cup
High on a lush, steep
hillside covered with coffee trees, a picker carries a heavy bag filled with a
long day's work. The bag contains ripe, red coffee cherries. Months from now,
the beans from that day's harvest might be the very ones you purchase at your
favorite store. Between the time that he picked them and you purchase them, the
beans went through a series of steps very much like this.
1. Planting
A coffee bean is
actually a seed. When dried, roasted and ground, it is used to brew coffee. But
if the seed is not processed, it can be planted and will grow into a coffee
tree.
Coffee seeds are
generally planted in large beds in shaded nurseries. After sprouting, the
seedlings are removed from the seed bed to be planted in individual pots in
carefully formulated soils. They will be watered frequently and shaded from
bright sunlight until they are hearty enough to be permanently planted.
Planting often takes place during the wet season, so that the soil around the
young trees remains moist while the roots become firmly established.
2. Harvesting the Cherries
Depending on the
variety, it will take approximately 3 or 4 years for the newly planted coffee
trees to begin to bear fruit. The fruit, called the coffee cherry, turns a
bright, deep red when it is ripe and ready to be harvested. In most countries,
the coffee crop is picked by hand, a labor-intensive and difficult process,
though in places like Brazil, where the landscape is relatively flat and the
coffee fields immense, the process has been mechanized. Whether picked by hand
or by machine, all coffee is harvested in one of two ways:
Strip Picked - the entire crop is harvested at one time.
This can either be done by machine or by hand. In either case, all of the
cherries are stripped off of the branch at one time.
Selectively Picked - only the ripe cherries are harvested and
they are picked individually by hand. Pickers rotate among the trees every 8 -
10 days, choosing only the cherries which are at the peak of ripeness. Because
this kind of harvest is labor intensive, and thus more costly, it is used
primarily to harvest the finer arabica beans.
In most coffee-growing
countries, there is one major harvest a year; though in countries like
Colombia, where there are two flowerings a year, there is a main and secondary
crop. A good picker averages approximately 100 to 200 pounds of coffee cherry a
day, which will produce 20 to 40 pounds of coffee beans. At the end of a day of
picking, each worker's harvest is carefully weighed and each picker is paid on
the merit of his or her work. The day's harvest is then combined and
transported to the processing plant.
3. Processing the Cherries
Once the coffee has
been picked, processing must begin as quickly as possible to prevent spoilage.
Depending on location and local resources, coffee is processed in one of two
ways.
The Dry Method
This is the age-old method of processing coffee and is still used in many
countries where water resources are limited. The freshly picked cherries are
simply spread out on huge surfaces to dry in the sun. In order to prevent the
cherries from spoiling, they are raked and turned throughout the day, then
covered at night, or if it rains, to prevent them from getting wet. Depending
on the weather, this process might continue for several weeks for each batch of
coffee. When the moisture content of the cherries drops to 11 percent, the
dried cherries are moved to warehouses where they are stored .
The Wet Method
In wet method processing, the pulp is removed from the coffee cherry after
harvesting and the bean is dried with only the parchment skin left on. There
are several actual steps involved. First, the freshly harvested cherries are
passed through a pulping machine where the skin and pulp is separated from the
bean. The pulp is washed away with water, usually to be dried and used as
mulch. The beans are separated by weight as they are conveyed through water
channels, the lighter beans floating to the top, while the heavier, ripe beans
sink to the bottom.
Next they are passed
through a series of rotating drums which separate them by size.
After separation, the
beans are transported to large, water-filled fermentation tanks. Depending on a
combination of factors -- such as the condition of the beans, the climate and
the altitude -- they will remain in these tanks for anywhere from 12 to 48 hours.
The purpose of this process is to remove the slick layer of mucilage (called
the parenchyma) that is still attached to the parchment; while resting in the
tanks, naturally occurring enzymes will cause this layer to dissolve. When
fermentation is complete the beans will feel rough, rather than slick, to the
touch. At that precise moment, the beans are rinsed by being sent through
additional water channels. They are then ready for drying.
4. Drying the Beans
If the beans have been
processed by the wet method, the pulped and fermented beans must now be dried
to approximately 11 percent moisture to properly prepare them for storage.
These beans, still encased inside the parchment envelope (the endocarp), can be
sun dried by spreading them on drying tables or floors, where they are turned
regularly, or they can be machine dried in large tumblers. Once dried, these
beans, referred to as 'parchment coffee,' are warehoused in sisal or jute bags
until they are readied for export.
5. Milling the Beans
Before it is exported,
parchment coffee is processed in the following manner:
Hulling
Machines are used to remove the parchment layer (endocarp) from wet processed
coffee. Hulling dry processed coffee refers to removing the entire dried husk
-- the exocarp, mesocarp & endocarp -- of the dried cherries.
Polishing
This is an optional process in which any silver skin that remains on the beans
after hulling is removed in a polishing machine. While polished beans are
considered superior to unpolished ones, in reality there is little difference
between the two.
Grading & Sorting
Before being exported, the coffee beans will be even more precisely sorted by
size and weight. They will also be closely evaluated for color flaws or other
imperfections.
Typically, the bean
size is represented on a scale of 10 to 20. The number represents the size of a
round hole's diameter in terms of 1/64's of an inch. A number 10 bean would be
the approximate size of a hole in a diameter of 10/64 of an inch and a number
15 bean, 15/64 of an inch. Beans are sized by being passed through a series of
different sized screens. They are also sorted pneumatically by using an air jet
to separate heavy from light beans.
Next defective beans
are removed. Though this process can be accomplished by sophisticated machines,
in many countries, it is done by hand while the beans move along an electronic
conveyor belt. Beans of unsatisfactory size, color, or that are otherwise
unacceptable, are removed. This might include over-fermented beans, those with
insect damage or that are unhulled. In many countries, this process is done
both by machine and hand, insuring that only the finest quality coffee beans
are exported.
6. Exporting the Beans
The milled beans, now
referred to as 'green coffee,' are ready to be loaded onto ships for transport
to the importing country. Green coffee is shipped in either jute or sisal bags
which are loaded into shipping containers, or it is bulk shipped inside
plastic-lined containers. Approximately seven million tons of green coffee is
produced worldwide each year.
7. Tasting the Coffee
At every stage of its
production, coffee is repeatedly tested for quality and taste. This process is
referred to as 'cupping' and usually takes place in a room specifically
designed to facilitate the process. First, the taster -- usually called the
cupper -- carefully evaluates the beans for their overall visual quality. The
beans are then roasted in a small laboratory roaster, immediately ground and
infused in boiling water, the temperature of which is carefully controlled. The
cupper "noses" the brew to experience its aroma, an integral step in
the evaluation of the coffee's quality. After letting the coffee rest for
several minutes, the cupper "breaks the crust" by pushing aside the
grounds at the top of the cup. Again the coffee is nosed before the tasting
begins.
To taste the coffee,
the cupper "slurps" a spoonful with a quick inhalation. The objective
is to spray the coffee evenly over the cupper's taste buds, and then
"weigh" it before spitting it out. Samples from a variety of batches
and different beans are tasted daily. Coffees are not only analyzed this way
for their inherent characteristics and flaws, but also for the purpose of
blending different beans or determining the proper roast. An expert cupper can
taste hundreds of samples of coffee a day and still taste the subtle
differences between them.
8. Roasting the Coffee
Roasting transforms
green coffee into the aromatic brown beans that we purchase, either whole or
already ground, in our favorite stores. Most roasting machines maintain a
temperature of about 550 degrees Fahrenheit. The beans are kept moving
throughout the entire process to keep them from burning and when they reach an
internal temperature of about 400 degrees, they begin to turn brown and the
caffeol, or oil, locked inside the beans begins to emerge.
This process, called
pyrolysis is at the heart of roasting. It is what produces the flavor and aroma
of the coffee we drink. When the beans are removed from the roaster, they are
immediately cooled either by air or water. Roasting is generally performed in
the importing countries because freshly roasted beans must reach the consumer
as quickly as possible.
9. Grinding Coffee
The objective of a
proper grind is to get the most flavor in a cup of coffee. How coarse or fine
the coffee is ground depends on the method by which the coffee is to be brewed.
Generally, the finer the grind the more quickly the coffee should be prepared.
That is why coffee ground for use in an espresso machine is much finer than
coffee which will be brewed in a drip system.
10. Brewing Coffee
Before you brew your
coffee, take a moment to look carefully at the beans. Smell their aroma. Think
of the many processes that these beans have gone through since the day they
were hand-picked and sorted in their origin country. Consider the long way they
have traveled to your kitchen. Prepare your coffee thoughtfully and enjoy it
with pleasure. Many people have been instrumental in bringing it to your cup!
Source: National Coffee Associate, USA. Retrieved on March 6, 2015 from
http://ncausa.org/i4a/pages/index.cfm?pageid=68
