The following is an article from The Annals of Improbable Research.
An analysis of the world’s rarest and most expensive coffee
by Massimo F. Marcone, Ph.D., C.Chem., Chimiste (PQ) Adjunct Professor, Department of Food Science University of Guelph, Guelph, Ontario, Canada
[EDITOR’SNOTE: Kopi Luwak (sometimes spelled Kopi Luak) is a rare and prized variety of coffee. It was the subject of the 1995 Ig Nobel Prize in the field of Nutrition. Professor Marcone’s work, described here, advances our understanding of Kopi Luwak. Title image by Praveenp.]
No coffee is perhaps in shorter supply and has a more distinct flavor and history than “Kopi Luwak” from Indonesia. With an annual production of less than 500 pounds and a price tag of 500-600 dollars (Canadian) per pound, it commands the undisputed reputation of being the rarest and most expensive coffee in the world. This is indeed a unique coffee, as it is processed through the digestive system of a palm civet (Paradoxurus hermaphroditus). This three-to-ten pound arboreal animal uses its keen sense of eyesight during the night to smell and seek out only the ripest reddish coffee cherries to eat. The coffee cherry fruit is completely digested by the civet, whereas the actual coffee beans are excreted in their feces, being deposited in civetries. These are ultimately collected and washed by local coffee collectors. The internal fermentation and action by different digestive enzymes add a unique flavor to the beans. This flavor has been described as earthy, musty, syrupy, smooth, and rich with both jungle and chocolate undertones.
The author displays some coffee beans.
Curiously, Kopi Luwak is not the first nor the only food that-- prior to human consumption-- makes a passage through the entire, or partial, digestive tract of an animal.