Coffee is made from the seeds of the Coffea plant. The two most commonly grown varieties of the coffee plant are robusta and arabica. Coffee berries and their seeds undergo multi-step processing before they become a beverage ready for consumption. The berries are picked, processed, and dried. The seeds are roasted at temperatures around 200°C (392°F), during which the sugars in the bean caramelize, the bean changes color, and flavor develops. The beans are roasted to a light, medium, or dark brown color, depending on the desired flavor. Then, the roasted beans are ground and brewed in order to create the beverage coffee.

Coffee has played a role in many societies throughout history. In Africa and Yemen, it was used in religious ceremonies. In the 17th century, it was banned in Ottoman Turkey. In Europe, it was once associated with rebellious political activities. Today, the trade of coffee has a large economic impact. Coffee is one of the world's most important primary commodities, as it is a popular beverage world wide; in 2003, coffee was the world's sixth largest legal agricultural export in value. 6.7 million tons of coffee were produced annually from 1998–2000, and it is predicted that by 2010, production will rise to 7 million tons annually.

The health effects of coffee have been questioned, and many studies have been performed on the relationship between coffee consumption and many medical conditions. Studies have suggested that the consumption of coffee lowers the risk of certain diseases, but coffee consumption, especially when it is excessive, may have negative effects as well.

A beverage as black as ink, useful against numerous illnesses, particularly those of the stomach. Its consumers take it in the morning, quite frankly, in a porcelain cup that is passed around and from which each one drinks a cupful. It is composed of water and the fruit from a bush called bunnu.

Roasting coffee transforms the chemical and physical properties of green coffee beans into roasted coffee products.
The roasting process is integral to producing a savory cup of coffee. When roasted, the green coffee bean expands to nearly double its original size, changing in color and density. As the bean absorbs heat, the color shifts to yellow and then to a light "cinnamon" brown then to a dark and oily color. During roasting oils appear on the surface of the bean. The roast will continue to darken until it is removed from the heat source.

At lighter roasts, the bean will exhibit more of its "origin flavor" - the flavors created in the bean by the soil and weather conditions in the location where it was grown. Coffee beans from famous regions like Java, Kenya, Hawaiian Kona, and Jamaican Blue Mountain are usually roasted lightly so their signature characteristics dominate the flavor.