Ruwak, the most expensive coffee in the world.

Although Blue Mountain coffee is considered the most expensive coffee in the world, at around $40 a pound, it pales in comparison to another Sumatra crop that can sell for $300 a pound. This is the infamous Rook coffee.

Usually, coffee fruit is picked, or by sun or water washing method, to remove the skin, pulp and silver, but luwak coffee is the use of natural fermentation in the animal digestive system, to extract coffee beans. Indonesian mountain civets like to eat a coffee fruit called luwak. The fruit eaten by the civets, however, cannot be digested and the coffee beans are excreted in the civets 'droppings. Indonesians discovered that luwak coffee beans fermented in the stomach of civets had a rare and peculiar aroma, so they collected civets feces and used the isolated coffee beans to brew coffee. Due to its low yield, it is the most expensive coffee in the world.