Summer 2023

Natural Selections

Professor Jomkhwan Meerak talking to two graduate students, an undergraduate student, and civet farm owner sitting at a table.
Professor Jomkhwan Meerak discusses the details of civet coffee with a civet farm owner (center) while two Chiang Mai University graduate students (left) and Aisha Inuwa BS'16, a CALS microbiology major at the time (right), listen in. Photo by Jon Roll


Thailand produces some of the most expensive coffee in the world, as much as $100 a cup or $600 per pound in some countries. The premium price stems from its unique origins: Between harvest and roasting, its beans pass through the guts of wild, catlike mammals called civets. But thanks to an international collaboration between Thai and CALS researchers, there’s a new bioengineered version of civet coffee that takes the civet out of the process.

First, some history. When the Dutch were making a fortune in the spice trade in the 1700s, plantation owners imported coffee from the Middle East to grow in Southeast Asia. Workers were forbidden from consuming the expensive crop, but they noticed that when wild civets ate the ripe coffee cherries, they excreted the seeds (or beans) intact. The workers collected, cleaned, and roasted the scat-captured beans and used them to brew a mellow coffee. Due to digestive processes in the civet’s gut, this coffee is lower in acid and has a chocolatey caramel flavor, with hints of musk.

Jon Roll BS’88, PhD’96, a member of the teaching faculty in the Department of Bacteriology, met his first civet on a motorcycle tour of northern Thailand. He’s been traveling there since 2003 to help set up CALS students in summer undergraduate research internships at Thai universities. He also teaches a UW course, Microbio 304, at Mae Fah Luang University, in the postcard-pretty mountains of Chiang Rai.

An Asian palm civet standing in a cage.
An Asian palm civet, native to South and Southeast Asia. The coffee beans these civets eat and defecate are used to brew coffee with a distinctive (and expensive) flavor. Photo by Wikimedia Commons/Pondeyo, CC BY-SA 4.0

Roll visited a civet coffee company where women in the colorful costumes of the hill tribes, their teeth dyed black with betel juice, sifted through civet feces to glean digested beans. He also toured a civet farm, where the two-pound animals were kept in wire cages that have prompted animal rights activists to call for a boycott of civet coffee.

“The coffee is clearly being changed by going through the civet’s gut, but what is going on in the process?’’ Roll wondered at the time. And he thought he might find the answer by working with Thai researcher Jomkhwan Meerak, of Chiang Mai University, whom he met when he was placing student interns. They decided to compare the microbiome of civets that were eating coffee cherries to those that weren’t.

Roll introduced Meerak to bacteriology professor Garret Suen, whose lab has studied the microbiomes of animals ranging from dairy cattle to ground squirrels. Back in Thailand, Meerak’s lab obtained the civet feces samples and extracted DNA, and Roll brought the DNA to Madison for microbiome analysis through an advanced genomic research method called next generation sequencing.

A bowl of roasted "post-civet" beans, a cup of a brewed civet coffee, and a basket of dried civet coffee beans arranged on a table.
Counterclockwise from top, a basket of coffee beans that were dried after being consumed and excreted by civets, a bowl of roasted “post-civet” beans, and a cup of brewed civet coffee. Photo by Jon Roll

It turned out that certain species of lactic acid bacteria and yeast were driving the process. One member of Suen’s lab was Thai student Chutikarn Chitboonthavisuk MS’18, now a doctoral candidate working in the lab of biochemistry professor Vatsan Raman. Bacteriology professor Daniel Amador-Noguez and his lab team also got involved in the civet research, identifying metabolites from the process.

Meerak and graduate student Teerawat Ngamnock have used the discovery to establish a civet-friendly coffee company, called BIRTH 2022, that uses an innovative process with probiotic starters of lactic acid bacteria and yeast isolated from the civets to ferment organic coffee beans. This produces a cold-brewed espresso with special flavors and higher levels of bioactive substances that may be anti-inflammatory immune boosters. The special brew’s name: Beyond Coffee.

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