A brief history of Coffee:
Coffee was first consumed in the 9th Century, when it was discovered in the highlands of Ethiopia. From there, it spread to Egypt and Yemen, and by the 15th Century had reached Azerbaijan, Persia, Turkey, and northern Africa. From the Muslim world, coffee spread to Italy, then to the rest of Europe, to Indonesia and to the Americas. Today, coffee is one of the most popular beverages worldwide. Coffee is the second-most-traded physical commodity in the world...
Coffee berries, which contain the coffee bean, are produced by several species of small evergreen bush of the genus Coffea. The two most commonly grown species are Coffea canephora (also known as Coffea robusta) and Coffea arabica. These are cultivated in Latin America, Southeast Asia, and Africa. Once ripe, coffee berries are picked, processed, and dried. The seeds are then roasted, undergoing several physical and chemical changes. They are roasted to varying degrees, depending on the desired flavor. They are then ground and brewed to create coffee...
Darker roasts are generally smoother, because they have less fiber content and a more sugary flavor. Lighter roasts have more caffeine, resulting in a slight bitterness, and a stronger flavor from aromatic oils and acids otherwise destroyed by longer roasting times. A small amount of chaff is produced during roasting from the skin left on the bean after processing. Chaff is usually removed from the beans by air movement, though a small amount is added to dark roast coffees to soak up oils on the beans. 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 beans in hot water 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...
Depending on the type of coffee and method of preparation, the caffeine content of a single serving can vary greatly. On average, a single cup of coffee of about 207 milliliters (7 fluid ounces) or a single shot of espresso of about 30 mL (1 oz) can be expected to contain the following amounts of caffeine...
For full article and list of sources check out: http://en.wikipedia.org/wiki/Coffee
