Decaffeination is a process through which caffeine is removed from a batch of coffee beans. Decaffeination occurs after the beans are processed and sorted for market, but prior to roasting. After this process, the resulting coffee beans will not be COMPLETELY free of caffeine, but they will contain a significantly reduced level of the chemical.
Acting on an idea from the poet Johann von Goethe, in 1820 Friedrich Ferdinand Runge first isolated caffeine as the cause of insomnia in coffee drinkers. Initial attempts at decaffeinating coffee involved applying solvents to already roasted coffee beans. While it was easier to remove the caffeine from a roasted bean (the solvents did not adequately penetrate unroasted beans), the flavor and aroma were also adversely affected. In subsequent efforts, green coffee beans were broken or ground so that the solvents could better extract the caffeine. However, pre-ground coffee proved too difficult to roast adequately.
In 1906, Ludwig Roselius developed a commercially viable method of extraction. He accidentally discovered that by steaming unroasted coffee beans so that they would expand, he could then extract much of the caffeine by applying benzene. Roselius would patent this method in 1908 and go on to found the brand of decaffeinated coffee that would eventually become Sanka, now a sub-brand of Kraft General Foods's Maxwell House brand. In the United States, the Merck pharmaceutical company would soon sell his coffee as Dekafa.
As the health effects of benzene became better known, other solvents replaced benzene in the decaffeination process. One of these was methylene chloride, which, though it too has adverse health effects, continues to be used in the KVW decaffeination method.
- William H. Ukers (1922). “The Chemistry of the Coffee Bean”, All about Coffee, 161. ISBN 0810340925.
- Constantina Tzia, George Liadakis (2003). “Flavor and Aroma Substances”, Extraction Optimization in Food Engineering, 456.
- Mark Pendergrast (1999). “Coffee Colonizes the World”, Uncommon Grounds: The history of coffee and how it transformed our world, 110. ISBN 0465054676.