November 2, 2024

A Simple Splash of Water: The Scientific Breakthrough for Superior Espresso

Adding water to coffee beans before grinding them can significantly reduce static electrical energy, leading to a richer and more consistent espresso, possibly transforming coffee industry practices.
These improvements to coffee extraction might have massive financial ramifications for the coffee industry, which deserves $343.2 billion or 1.5% of the United States gross domestic product, the scientists state. “Pushing the concentration up by 10%– 15% for the exact same dry coffee mass has substantial ramifications for saving money and improving quality,” states Hendon.
Checking out the Causes of Coffee Electrification
That coffee grinding produces fixed electricity has long been known within the coffee market, where this electrification causes clumping and occasional zaps, however little bit was learnt about how different coffee attributes contribute to this phenomenon or how it affects brewing. To recognize aspects connected with static electricity generation during coffee grinding, Hendon coordinated with volcanologists who study comparable electrification processes throughout volcanic eruptions.
” During eruption, magma breaks up into lots of little particles that then come out of the volcano in this huge plume, and throughout that entire procedure, those particles are rubbing against each other and charging up to the point of producing lightning,” says first author and volcanologist Joshua Méndez Harper at Portland State University. “In a simplistic method, its similar to grinding coffee, where youre taking these beans and minimizing them to great powder.”
This video demonstrates how coffee acts when grinding with and without a splash of water. Credit: Joshua Mendez Harper
The scientists determined the amount of fixed electrical energy produced when they ground various commercially and internal roasted coffee beans that differed by elements including native land, processing method (natural, washed, or decaffeinated), roast color, and wetness material. They also compared the effect of grinding coarseness on the quantity of electricity produced.
There was no association in between fixed electrical energy and the coffees native land or processing technique, however the researchers did discover associations between electrification and water content, roast color, and particle size. Less electrical energy was produced when coffee had a higher internal moisture material and when coffee was ground at a coarser setting. Light roasts produced less charge, and this charge was more likely to be favorable, while darker roasts– which also tend to be drier– charged negatively and produced more total charge. The scientists likewise revealed that dark roast coffees produce much finer particles than light roasts when ground at the exact same setting.
Improving Espresso Brewing
Next, the team evaluated whether grinding with water altered the way espresso is brewed. When they compared espresso made with identical coffee beans ground either with or without a splash of water, they found that grinding with water resulted in a longer extraction time and a stronger brew. Grinding with water likewise resulted in espresso shots that were more comparable from shot to shot, overcoming a significant difficulty for baristas and industrial coffee makers.
Though they only tested espresso, the scientists say these benefits would use to numerous other brewing approaches. “The main material advantage of including water throughout grinding is that you can pack the bed more largely since theres less clumping,” says Hendon. “Espresso is the worst culprit of this, however you would also see the advantage in brew formats where you put water over the coffee or in little percolation systems like a stovetop Bialetti. Where youre not visiting a benefit throughout developing is for techniques like the French press, where you immerse the coffee in water.”
Future Research and Broader Implications
The scientists prepare to follow up with more examinations into how to prepare the best coffee. “Now that we know what grind settings to use to make reproducible espresso, we can begin to attempt to understand what factors trigger sensory distinctions in coffee taste,” states Hendon.
Their work likewise has implications beyond the everyday brew, as the electrification of granular materials is an active location of research in material science, geophysics, and engineering.
” Its sort of like the start of a joke– a coffee and a volcanologist expert stroll into a bar and after that come out with a paper,” says Méndez Harper, “but I think there are a lot more chances for this sort of collaboration, and theres a lot more to learn about how coffee breaks, how it flows as particles, and how it interacts with water. These investigations might assist fix parallel concerns in geophysics– whether its landslides, volcanic eruptions, or how water percolates through soil.”
Reference: “Moisture-controlled triboelectrification throughout coffee grinding” by Joshua Méndez Harper, Connor S. McDonald, Elias J. Rheingold, Lena C. Wehn, Robin E. Bumbaugh, Elana J. Cope, Leif E. Lindberg, Justin Pham, Yong-Hyun Kim, Josef Dufek and Christopher H. Hendon, 6 December 2023, Matter.DOI: 10.1016/ j.matt.2023.11.005.
This research was supported by the Department of Energy, the National Science Foundation, the Camille and Henry Dreyfus Foundation, and the Coffee Science Foundation with assistance from Nuova Simonelli.

Researchers have discovered that the fixed electricity produced during coffee grinding is affected by the beans moisture material. Including water before grinding reduces static and enhances espresso quality. These findings, using economic advantages to the $343.2 billion coffee industry, likewise enhance the consistency of espresso shots.
Adding moisture to coffee beans before grinding lowers fixed electrical energy, boosting espresso quality and offering significant benefits for the coffee market.
The fracturing and friction of coffee beans during grinding produces electrical power that causes coffee particles to clump together and adhere to the grinder. Scientist report on December 6 in the journal Matter that coffee beans with higher internal moisture produce less fixed electrical power, which suggests less coffee is wasted and there is less mess to clean up. This impact can be simulated by adding a little quantity of water to beans right away before grinding them. The team likewise showed that grinding with a splash of water produces more consistent and extreme espresso.
” Moisture, whether its residual wetness inside the roasted coffee or external moisture added during grinding, is what dictates the quantity of charge that is formed throughout grinding,” states senior author Christopher Hendon, a computational materials chemist at the University of Oregon. “Water not only reduces fixed electricity and for that reason decreases mess as youre grinding, but it can also make a major effect on the strength of the drink and, possibly, the capability to gain access to greater concentrations of favorable flavors.

The fracturing and friction of coffee beans throughout grinding creates electricity that causes coffee particles to clump together and stick to the mill. Scientist report on December 6 in the journal Matter that coffee beans with greater internal moisture produce less static electricity, which indicates less coffee is wasted and there is less mess to clean up. Less electrical power was produced when coffee had a greater internal wetness content and when coffee was ground at a coarser setting. When they compared espresso made with similar coffee beans ground either with or without a splash of water, they found that grinding with water resulted in a longer extraction time and a stronger brew. Grinding with water likewise resulted in espresso shots that were more similar from shot to shot, overcoming a significant hurdle for baristas and commercial coffee brewers.