








Beans from different countries or regions can usually be distinguished by differences in flavor, aroma, body, and acidity. These taste characteristics are dependent not only on the coffee's growing region, but also on genetic subspecies (varietals) and processing. Varietals are generally known by the region in which they are grown, such as Colombian, Java and Kona.
Coffee Processing

Then they are sorted by ripeness and color and the flesh of the berry is removed, usually by machine, and the seeds—usually called beans—are fermented to remove the slimy layer of mucilage still present on the bean. When the fermentation is finished, the beans are washed with large quantities of fresh water to remove the fermentation residue, which generates massive amounts of coffee wastewater. Finally, the seeds are dried. The best (but least used) method of drying coffee is using drying tables. In this method, the pulped and fermented coffee is spread thinly on raised beds, which allows the air to pass on all sides of the coffee, and then the coffee is mixed by hand. In this method the drying that takes place is more uniform, and fermentation is less likely. Most African coffee is dried in this manner and certain coffee farms around the world are starting to use this traditional method. Next, the coffee is sorted, and labeled as green coffee. Another way to let the coffee beans dry is to let them sit on a concrete patio and rake over them in the sunlight. Some companies use cylinders to pump in heated air to dry the coffee beans, though this is generally in places where the humidity is very high.
The Roasting Process


Grading the Roasted beans
Depending on the color of the roasted beans as perceived by the human eye, they will be labeled as light, medium light, medium, medium dark, dark, or very dark. A more accurate method of discerning the degree of roast involves measuring the reflected light from roasted beans illuminated with a light source in the near infrared spectrum. This elaborate light meter uses a process known as spectroscopy to return a number that consistently indicates the roasted coffee's relative degree of roast or flavor development.
Roast characteristics

Decaffeination
Decaffeination may also be part of the processing that coffee seeds undergo. Seeds are decaffeinated when they are still green. Many methods can remove caffeine from coffee, but all involve either soaking the green beans in hot water (often called the "Swiss water" process) or steaming them, then using a solvent to dissolve caffeine-containing oils. Decaffeination is often done by processing companies, and the extracted caffeine is usually sold to the pharmaceutical industry.
Preparation

Coffee may be brewed by several methods: boiled, steeped, or pressured

Coffee may also be brewed in cold water, resulting in a brew lower in acidity than most hot-brewing methods produce, by steeping the coarsely ground beans in cold water for several hours, then filtering them.
Presentation

Espresso-based coffee has a wide variety of possible presentations. In its most basic form, espresso is served alone as a shot or with hot water added, known as Caffè Americano. Reversely, long black is made by pouring espresso in water, which retains the crema compared to Caffè Americano. Milk is added in various forms to espresso: steamed milk makes a caffè latte, equal parts steamed milk and milk froth make a cappuccino, and a dollop of hot foamed milk on top creates a caffè macchiato. The use of steamed milk to form patterns such as hearts or maple leaves is referred to as latte art.
A number of products are sold for the convenience of consumers who do not want to prepare their own coffee.


Coffee can also be incorporated with alcohol in beverages—it is combined with whiskey in Irish coffee, and forms the base of alcoholic coffee liqueurs such as Kahlúa, and Tia Maria.
Reference: http://en.wikipedia.org/wiki/Coffee