Removing caffeine from the bean is an industry in its own right, born in Bremen in 1905. It now has its own plate, because the subject has its chemistry, its patents and its ongoing regulatory dispute, and it largely overflows this section.

There one finds the chemistry that makes the operation difficult, and the processes one by one, from benzene to supercritical CO₂. One also finds the ongoing dispute over methylene chloride, and what the bean loses in the operation, in measured figures. Then how to roast it, the few factories in the world that know how to do it, and what becomes of the caffeine taken out of it. See decaf.