Not to be a downer, but it is a universal truth that the world is getting increasingly expensive. From textiles to groceries and other basic consumer goods, unless we’re all about to make a nice windfall in the next financial quarter, most of the global population will have to take these price hikes on the chin. But what about our creature comforts? Highly caffeinated coffee is one of the binders holding many of our post-industrial lives together, making minor inconveniences less noticeable and major ones a little more bearable. But with recent strains on the climate from consecutive seasons of adverse weather, the price of raw arabica beans — the most widely used species of coffee bean — has spiked, with no sign of coming down. Thankfully, scientists also need caffeine to survive, and in lieu of creating a more potent tea leaf, they discovered a more powerful, cost-effective way to brew coffee. Courtesy of iStock.com/Jag_cz. The method, developed by researchers at the University of Pennsylvania, has more to do with the pour than the actual beans themselves, allowing the at-home barista the ability to create a stronger brew with less grounds. It involves a pour-over technique using a gooseneck kettle. This provides an even, controlled pour and creates a laminar, or a smooth and nonturbulent flow of water over a bed of grounds for a more turbulent mixing effect. The process allows the water to extract and dissolve more of the coveted coffee flavor. Because it’s hard to see fluid dynamics in action in coffee due to its lovely mocha splendor, the researchers tested the technique using silica gel particles in a glass cone serving as a coffee filter stand-in. A laser sheet and high-speed camera allowed them to watch water streams create what they poetically called “miniature avalanches” of particles that revealed the flow’s inner workings. In doing so, they also discovered that the height from which the water is poured will determine the resulting strength of the coffee. Too low of a pour resulted in a gentle spread that wouldn’t effectively mix the grounds, while too high of a pour resulted in the laminar breaking apart into droplets, which can decrease coffee extraction due to the added air in those droplets. Attaining the happy median between these two allows the water to effectively penetrate farther into the bed of coffee grounds, enabling a higher surface area of water coverage and a better steep, without additional air in the coffee cone. Though brewing at home helps the wallet, the search for a better morning cup wasn’t the by-product of caffeine-starved physicists, but rather this finding occurred during a grander scope of research within the university. The broader aspirations of this work include creating microscale active surfaces that use rotating magnetic fields to clean biofilms from medical devices, investigating ultrafast biological flows, understanding rock erosion under waterfalls, and looking at wastewater treatment. While humanity’s love of java was not the motivation behind this discovery, the researchers’ findings have nonetheless laid the groundwork to help make sure that coffee enthusiasts get more kick out of their cup while saving a few beans. So, until there’s a fruitful growing season that generates an arabica surplus, or another research group comes along to develop a new caffeinated elixir, consider the height of your next pour over those coffee grounds. The research was published in Physics of Fluids (www.doi.org/10.1063/5.0257924).