The quest for naturally caffeine-free coffee continues:
Researchers have long sought a better bean, harvested directly from the plant caffeine-free. This would preserve coffee's complex flavour and give growers a high-end slice of the decaf market. But developing such a bean through conventional breeding or even genetic modification has proved more difficult than anyone anticipated. … Today, companies may instead douse raw green coffee beans in high-pressure liquid carbon dioxide or soak them in hot water for several hours to remove the caffeine before roasting. Aficionados say that all these methods destroy the taste, but the decaf market is still worth US$2 billion a year.
Veronique Greenwood eyes the hurdles:
Hope and heartbreak mix in equal proportions in this story: find a promising plant, watch its flowers wither before they are ready to be fertilized; come with a dynamo technique, suffer cripplingly small yields. John Stiles of University of Hawaii, after triumphing over the mysterious unwillingness of C. arabica cells to take up new genetic material and starting a private lab to develop his creations, found that as they grew, caffeine began creeping into their tissues. Nearly a decade after Paulo Mezzaferra found that he’d made plants with miniscule levels of caffeine, he is still struggling to get them to thrive.
The Dish 