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. Several varieties of green coffee usually are blended and roasted together to produce the tastes, aromas, and flavors popular with consumers. As a rule the beans are heated in rotating, horizontal drums that provide a tumbling action to prevent uneven heating or scorching. The roasted beans are cooled rapidly. Ground coffee loses its unique flavor within about a week unless it is specially packaged.