NYT: Trace elemental analysis to determine fake Kona coffee

Via the New York Times, this fascinating news about coffee farmers in Hawaii using chemistry to prevent counterfeiting of "Kona" coffee: 

...Mr. Corker said farmers had long been frustrated by the ubiquitous “Kona” beans sold by souvenir stores, coffee shops and larger retailers. They strongly suspected that the products were fake: They were far too cheap.

In 2013, a U.S. Supreme Court case caught Mr. Corker’s attention. The court found that Pom Wonderful, which sells pomegranate juice, was allowed to sue Coca-Cola for marketing a “Pomegranate Blueberry” juice that was in fact more than 99 percent apple and grape juices.

“The decision said, if you’re harmed by false labeling, you can bring a case for damages,” Mr. Corker said.

In 2019, he filed the lawsuit on behalf of Kona farmers against more than 20 companies. At the center of the complaint was a chemical analysis performed at a private lab in Salt Lake City.

James Ehleringer, a biologist at the University of Utah who ran the analysis, said that standard tests depended on the amount of water in each sample. That wouldn’t have worked on the variety of Kona products at issue.

“As you go from green beans to roasted beans, you’re changing the water content,” he said. So he borrowed an approach from geology that instead looked at the relative concentrations of rare, inorganic minerals in the beans. These ratios, he said, stay constant even at roasting temperatures.

After testing coffee samples from around the world as well as more than 150 samples from Kona farms, Dr. Ehleringer’s team identified several element ratios — strontium to zinc, for example, and barium to nickel — that distinguished Kona from non-Kona samples. “We were able to establish a fingerprint for Kona,” said Dr. Ehleringer, who described the general method in a 2020 study. “It’s the characteristics of the volcanic rock.”

Apparently Dr. Ehleringer's work hasn't been replicated by other labs, but it seems to me that the farmers of Kona coffee are incentivized to figure out and lock down what the chemical "terroir" of Kona coffee, and to harry the fakers out of business.