Electrical current might be the key to a better cup of coffee

At the University of Oregon, chemist Christopher Hendon has turned his passion for coffee into a groundbreaking research initiative. His latest exploration focuses on a unique method of assessing coffee’s flavor profile by applying an electrical current to the beverage. This innovative approach is detailed in a recent study published in *Nature Communications*. Hendon has been delving into the intricacies of coffee brewing for years. Back in 2020, his lab developed a mathematical model aimed at consistently crafting the ideal espresso while minimizing waste. This intricate process involves extracting flavors from approximately 2,000 compounds present in coffee grounds during brewing, making it challenging for baristas to replicate the perfect cup each time. To address this, Hendon and his team formulated a model that assesses a measurable property known as extraction yield (EY), which represents the amount of coffee dissolved in the final drink. This yield is influenced by the control of water flow and pressure as it brews through the coffee grounds. Their model draws parallels with lithium ions in battery electrodes, akin to how caffeine dissolves from the grounds. Three years later, the research took a new direction, focusing on the microscopic clumps that form during grinding, especially with finely ground coffee. Hendon identified static electricity generated by the grinding process as the primary culprit behind these clumps. He hypothesized that reducing this static could help eliminate the issue. The phenomenon, known as triboelectricity, arises from the accumulation of opposite electric charges when two materials come into contact. To further investigate, Hendon collaborated with volcanologists Josef Dufek and Joshua Méndez Harper, who shared his passion for coffee and recognized parallels between coffee science and volcanic activity. Their experiments revealed that simply adding a small amount of water to coffee beans prior to grinding can significantly diminish static charge, thereby reducing clumping during brewing. This method not only minimizes waste but also enhances the uniform flow necessary for brewing a delicious espresso. While skilled baristas have long utilized this technique, known as the Ross droplet method, this study marks a significant first in scientifically validating its effectiveness and measuring the electrical charge in various coffee types.