sciencehabit writes "People who enjoy the most expensive coffee in the world can soon sip without worry: Researchers have come up with a way to tell if their cuppa joe is real or faux. The luxury drink in question—Kopi Luwak—is produced from coffee beans pooped out by the palm civet, a time-consuming process that helps contribute to the beverage's price tag of between $330 to $500 per kilogram. In a new study, researchers chemically analyzed four different blends of coffee—authentic Kopi Luwak, regular coffee, a 50/50 mix of the two, and a brew of coffee beans that producers had chemically treated in an attempt to simulate mammalian digestion. Of the hundreds of organic substances naturally present in coffee, a handful enabled the team to distinguish Kopi Luwak from the other brews. The technique may even be sensitive enough to distinguish pure Kopi Luwak from versions adulterated with varying percentages of other coffees—which offers some degree of reassurance when your morning mud costs about $15 a cup."