A volcanologist has revealed the secret to brewing a stronger espresso.
A study published in the journal Matter says that adding a splash of water to coffee beans before grinding them produces an espresso that is more intense and consistent. This is because when coffee beans are ground, electricity is generated that causes the particles to clump together and sometimes they stick to the insides of the grinder. But the new study found that beans with more moisture produce less electricity.
And, strangely, the process is dissimilar to the eruption of a volcano.
"During eruption, magma breaks up into lots of little particles that then come out of the volcano in this big plume, and during that whole process, those particles are rubbing against each other and charging up to the point of producing lightning," the paper's first author, volcanologist Joshua Méndez Harper, at Portland State University, said in a press release detailing the findings.
"In a simplistic way, it's similar to grinding coffee, where you're taking these beans and reducing them to fine powder," he said.
The researchers believe these findings could have hugely positive effects on the coffee industry. This is because a higher concentration of coffee, by around 10 to 15 percent, can save money as well as improve quality.
Researchers already knew that electricity was produced during the grinding process. But not much research has been done into how it affects the brewing process.
To reach their findings, senior author Christopher Hendon, a computational materials chemist at the University of Oregon, teamed up with volcanologists to compare the process with volcanic eruptions, thinking it would lead him to an answer.
First, they measured the amount of static electricity for coffee beans from different countries. These beans differed in roast color and moisture content. They also compared the amount of coarseness with the amount of electricity produced during grinding.
While they did not find any link between the electricity and different countries, they found links between the water content and the electricity.
"Moisture, whether it's residual moisture inside the roasted coffee or external moisture added during grinding, is what dictates the amount of charge that is formed during grinding," Hendon said in the press release.
"Water not only reduces static electricity and therefore reduces mess as you're grinding, but it can also make a major impact on the intensity of the beverage and, potentially, the ability to access higher concentrations of favorable flavors," he said.
The research does not end here. The team hopes to continue looking at more ways that scientifically explain how the perfect cup of coffee can be prepared.
"It's sort of like the start of a joke—a volcanologist and a coffee expert walk into a bar and then come out with a paper," Harper said.
"But I think there are a lot more opportunities for this sort of collaboration, and there's a lot more to know about how coffee breaks, how it flows as particles, and how it interacts with water," he continued. "These investigations may help resolve parallel issues in geophysics—whether it's landslides, volcanic eruptions, or how water percolates through soil."
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Robyn White is a Newsweek Nature Reporter based in London, UK. Her focus is reporting on wildlife, science and the ... Read more
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