The water is evaporated from the extract by various methods, including the use of spray driers or high-vacuum equipment. In freeze-dried coffee the coffee extract is frozen, and the water is removed by sublimation. The product is packed in vacuumized, sealed jars or in cans. Caffeine can be removed from coffee by treating the green beans with chlorinated hydrocarbon solvents. The beans are roasted by ordinary procedures after removal of the solvents.
Decaffeinated coffee is used by people hypersensitive to the caffeine present in regular coffee.
In the 1980s nonchemical methods of decaffeination became more common. The flavor of coffee is determined not only by the variety, but also by the length of time the green beans are roasted. After roasting, the beans are usually ground and vacuum-packed in cans. Since the flavor of coffee deteriorates rapidly after it is ground, or after a sealed can is opened, many coffee drinkers buy whole roasted beans and grind them at home.