The decaffeination process works as follows. The green beans are soaked in water which causes them to double in size. The caffeine that was trapped in the bean is dissolved into the water. The soaked beans go into huge stainless steel extraction vessels, which are then tightly sealed. Liquid CO2 is pumped into the beans at enormous pressure. The CO2 acts as a solvent, absorbing the caffeine. Once the beans are caffeine-free, they are strained, dried and ready to be roasted.