When you pay $150 to $230 for a pound of exotic coffee, you want to know it’s the real deal. Now, a team of chemists say they’ve developed a way to verify that beans labeled as “civet coffee” are authentic.
What is civet coffee and what makes it so expensive? Normally, coffee farmers and processors pick the berries from their coffee trees, remove the fruits’ flesh from their seeds, ferment the seeds, and then wash, dry and roast the seeds. For civet coffee, a cute Southeast Asian forest creature called the Asian palm civet helps out with some of these steps. Civets selectively eat the best ripe coffee berries, and their digestive tracts strip the fruit from the beans. The civets then excrete the beans, which civet coffee farmers gather, wash, ferment and roast. Regular little Santa’s helpers, civets are!
So. Civet coffee, also known by its Indonesian name, Kopi Luwak, needs to be gathered by hand from civet poop, making it rare and labor-intensive to produce. That explains its price… as well as some coffee sellers’ inclination to try to market non-civet-processed coffee as Kopi Luwak, or to cut true Kopi Luwak with regular coffee. Those scams inspired a team of Japanese and Indonesian researchers to come up with a way to chemically distinguish regular coffee from civet coffee.
The researchers analyzed Kopi Luwak that they produced (presumably with civets in lab), as well as commercially sold Kopi Luwak and commercially sold regular coffee beans from different regions in Indonesia. They used gas chromatography and mass spectrometry, both techniques that tell chemists what molecules appear in a sample, to conduct a metabolomic analysis of the coffees. They found that digested coffee beans had significantly different levels of certain acids than non-digested beans. Perhaps the gastric juices and the microbes in the civet digestive system give beans a distinctive acid profile, the researchers wrote in a paper they published in July in the Journal of Agricultural and Food Chemistry.
The detectable differences were great enough that they could distinguish a 50-50 mix of Kopi Luwak and regular coffee from 100 percent Kopi Luwak, the researchers report.
This is the first time anyone has been able to determine what chemicals to look for when distinguishing Kopi Luwak from regular coffee, the researchers wrote. Their technique could work alone or in conjunction with the imperfect methods with which experts identify Kopi Luwak now—by its color and smell.