There are many types of coffee in the world, and the price can vary greatly. But the most expensive types of coffee are the ones that have been ingested and defecated. What makes this process so special? The answer, as usual with foods and beverages — is chemistry.
Kopi luwak, or civet coffee, refers to the seeds of coffee berries that have been eaten and defecated by the Asian palm civet. It’s also the market name for the coffee made from these beans. A kilogram of Kopi luwak costs over $200 at the very least, and generally goes at about $700.
The coffee berries are fed to civets — nocturnal mammal native to the tropical forests of Asia and Africa. The civets eat the berries, digest them, and then defecate. It is believed that the digestive process of the civets improves the quality and flavor of the coffee beans. Fermentation occurs in their bellies. Producers argue that this process improves coffee beans through two processes:
selection; if given the possibility, the civets only eat the best berries which will result in the best beans
fermentation; the civet’s Protease enzymes seep into the beans, making shorter peptides and more free amino acids, significantly changing the taste.
However, despite these claims, few objective assessments of taste are available, because the process of coffee production involves many steps (collection, roasting, aging, and brewing), and the health of the civet is also a significant factor which can alter the taste.
But while civet coffee used to be the most expensive option out there, the crows was recently taken by Black Ivory Coffee – a type of coffee consumed and defecated by elephants. However, while it costs over $1,100 per kilo, Black Ivory coffee has very limited availability, being sold only at a few luxury hotels and clubs, where the price is $50 for a cup. The high price of the product is largely due to the high amount of coffee cherries needed to produce the finished product:33 kilograms (72 pounds) of raw coffee cherries result in 1 kilogram (2 pounds) of the finished product. Most of the beans are not recoverable because they are chewed by the elephants.
There are also reports of similar processes occurring naturally with muntjacs and some species of birds.
What the science says
It’s clear for everybody that eating digested coffee should be different from eating… undigested coffee. But how exactly does this alter the taste? Several studies have examined the process in which the animal’s stomach acids and enzymes digest the beans’ covering and ferment the beans. The main thing is that the bitterness of the coffee is greatly reduced by the enzymes in the civet’s (or elephant’s) stomach. These secretions also carry proteolytic enzymes which break down the beans’ proteins.
Research by food scientist Massimo Marcone at the University of Guelph in Ontario, found that there are, indeed, significant differences in the taste and flavor of the coffee. His main conclusions were:
Protein structure had been altered, reducing bitterness and potentially impacting flavor.
Volatile compounds had significant differences compared to regular coffee, indicating there are changes in flavor.
According to his research, these changes also eliminate or greatly reduce coffee’s diuretic effect.
Controversy and animal welfare
Despite the general appreciation and the huge prices paid for elephant or civet coffee, there is also great controversy surrounding this technique. While the coffee is sold at a huge price, collectors in the Philippines only get about $20 per kilogram.
Also, while initially civet coffee beans were picked from wild civet excrement found around coffee plantations, opportunistic people started building “civet farms”, confining tens of thousands of animals to live in battery cage. They are force fed, unhealthy, and live in extremely cruel conditions. There is also the problem that most people don’t know about this – the general awareness is very low regarding the conditions in which the civets live.
‘”The conditions are awful, much like battery chickens”, said Chris Shepherd, deputy regional director of the conservation NGO, TRAFFIC southeast Asia. “The civets are taken from the wild and have to endure horrific conditions. They fight to stay together but they are separated and have to bear a very poor diet in very small cages. There is a high mortality rate and for some species of civet, there’s a real conservation risk. It’s spiralling out of control. But there’s not much public awareness of how it’s actually made. People need to be aware that tens of thousands of civets are being kept in these conditions. It would put people off their coffee if they knew”‘.
So, if you do want to taste this exquisite coffee, please be sure that it was harvested from civets in the wild, and not from civet farms. Don’t put a taint on what is otherwise a delicious and creatively obtained beverage.
Andrei's background is in geophysics, and he's been fascinated by it ever since he was a child. Feeling that there is a gap between scientists and the general audience, he started ZME Science -- and the results are what you see today.