The beginning of Christopher Hendon’s quest to understand how to make a good cup of coffee sounds like the setup to a joke: A chemistry graduate student walks into a coffee bar.
Indeed, the barista who greeted him could have laughed. After all, Hendon knew nothing about coffee. He preferred lattes, composed largely of warm milk. Instead, the barista accepted Hendon’s tastes and schooled the willing student with artful brews of specialty beans grown around the world.
Then came a batch of roasted beans from London. They tasted unexpectedly bad, both by espresso and filter methods. The barista appealed to the budding chemist for a solution. The answers launched Hendon into an unplanned scientific sideline. For the last 15 years, he has probed how the water chemistry, temperature and surface area affect the flavor extracted from ground beans.
Coffee isn’t Hendon’s main scientific gig. He was hired two years ago as part of the University of Oregon’s Energy and Sustainable Materials Initiative. But it’s fair to say a talk on computational chemistry would not have packed the house for two recent science pub lectures — even for environmentally conscious Eugeneans who would applaud the potential sustainable energy applications. No, people were keenly interested to hear Hendon spill the beans on how to brew the perfect cup of coffee.
The perfect cup turns out to be an elusive and complex goal. Let’s break down a few reasons why.
First, at least half the quality of a cup of coffee arises from the bean itself, Hendon estimates. Coffee grows as the seeds of fruit on trees in narrow climate zones in tropical mountainous areas. The type of plant, growing conditions and soil, and way the seeds are dried all influence the flavor. “Buy a good green product, get a good brown product,” Hendon said in early January at the Quack Chats pub talk at the Downtown Athletic Club.