While the question "Regular or decaf?" might bring to mind the color-coded coffee pots common in diners across America, we have German coffee merchant Ludwig Roselius to thank for the decaffeination process. In 1905, Roselius realized that caffeine could be removed from coffee beans with help from the hydrocarbon benzene, which is now a known carcinogen.

Thankfully for modern decaf drinkers, scientists discovered safer methods to decaffeinate coffee beans. Since caffeine is soluble in water, it can be removed via water processing or by using a direct solvent (such as ethyl acetate) to extricate the stimulant.