In Italian it means fast or made on the spur of the moment. In terms of coffee, it is a method of brewing that was invented to produce a single cup of coffee at the moment requested. It is a marvel of chemical and physical engineering which extracts all that is best from the coffee and no more. An espresso is brewed by forcing hot water at high pressure through finely ground coffee, producing a syrupy texture and powerful, sweet taste. Making a true espresso requires a special machine to produce the pressure necessary.
Caffeine is a natural component of coffee beans.
Both methods use a decaffeinating substance to remove caffeine from the beans. A decaffeinating agent is then mixed directly with the beans to remove caffeine. Finally, the beans are steamed and dried to remove the decaffeinating agent. The caffeinated water is then separated from the beans and decaffeinating agent is added to the water to remove the caffeine. Later, the decaffeinated water is reintroduced to the beans to restore any flavor which may have been extracted during the decaffeination process.