Soft or distilled water, conversely, has a chemical composition that does the opposite—and is actually bad at attaching to and “extracting” those aromatic coffee compounds. This is one of the reasons why beans brewed in one part of the country might taste differently when brewed the same way in another state.
Hendon is currently completing his post-doctoral work at MIT as a computational chemist and plans on continuing his foray into coffee research. In addition to his analysis on water, he’s recently published a paper on how temperature affects the coffee grinding process. According to Maxwell Colonna-Dashwood, an award-winning barista that Hendon has collaborated with, he’s well on his way to becoming the resident scientist for the specialty coffee community—a field which until recently, has largely lacked the scientific grounding that’s been present in other food industries.
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Hendon’s interest in coffee began in 2012, while he was working on his chemistry Ph.D. in Bath, England. Fed up with his roommate’s “dreadful” homebrew, a quick Google search for “good coffee” led Hendon to an independent specialty shop in London named Colonna & Smalls. There, he met Colonna-Dashwood, the co-owner of the store, whom he’d later learn was a U.K. Barista Champion and a World Barista Championship finalist.
Despite being a “know-it-all customer,” who initially seemed more confident in his own coffee judgment than Dashwood’s professional advice, Hendon and the barista eventually bonded over conversations about science and coffee. One day Colonna-Dashwood approached Hendon for help with a few questions, including understanding some water chemistry readings that came up during the roasting process.
“It became clear that in order to help him answer his questions, he needed to teach me coffee,” Hendon says. “And for him to understand the answer to the question, he needed to understand chemistry.”
The duo ultimately teamed up, publishing “Water for Coffee,” a book that expands on Hendon’s water study. Colonna-Dashwood also invited Hendon along to compete in the 2014 World Barista Championship in Italy, which he says was a turning point for spreading their research within the coffee community.
“It's got a huge audience, and a lot of ideas are explored there,” Colonna-Dashwood says. “They become the zeitgeist for next year maybe.” In addition to being a competition, the championships function like coffee-themed TED talks, proffering new techniques and research to the specialty world.
“It got people thinking about water in a different way,” says Benjamin Brewer, the director of quality control at Blue Bottle Coffee, a specialty coffee roaster and retailer based in California, known for its obsessively high-quality products. “In the industry, [water has] always been oversimplified.”