From Bean to Brew: The Benefit of Adding Water to Coffee Beans Before Grinding

Coffee, the cherished beverage of millions around the world, is not just a drink but an experience. The process of brewing coffee is an art, and like any art, it has its secrets. One such secret is the practice of adding water to coffee beans before grinding them. This technique, which may seem counterintuitive at first, has been shown to enhance the quality of the brew and make the grinding process less messy.

The Science Behind the Splash

The technique of adding a splash of water to coffee beans before grinding is known as the Ross Droplet Technique. The science behind this technique lies in the properties of static electricity. When coffee beans are ground, the friction between the beans and the grinder’s components, as well as between the beans themselves, generates static electricity. This static charge causes the ground coffee particles to repel each other, leading to flyaway grounds that create a mess.

Water, being a great conductor, can help dissipate this static charge. When the beans are lightly misted with water, the water molecules form a thin layer around each bean. As the beans are ground, and static begins to form, the water acts as a neutralizing agent, reducing the buildup of static electricity. Consequently, the coffee grounds are less likely to cling to the grinder’s walls or fly out onto your countertop.

Enhancing the Brew

The benefits of this technique extend beyond just reducing mess. A study conducted by Christopher Hendon at the University of Oregon found that adding around 20 microliters of water per gram of coffee — or around half a milliliter for a typical brew — can stop the grounds clumping together and improve the consistency and flavor of an espresso.

The study also found that the most important factor in determining the electrostatic charge, and so the clumpiness of the coffee, was the total moisture in the beans before grinding. Beans roasted to a darker color have less moisture, and this makes them more susceptible to clumping.

The Impact on the Coffee Industry

The implications of this finding are significant not just for the home brewer but also for the commercial coffee industry. The addition of water before grinding could save hundreds of millions of dollars for commercial coffee companies. This is because the resulting ground coffee is less clumpy and so more water can percolate through it, reducing the amount of coffee beans you need to make a brew of a certain strength>


A simple splash of water on your coffee beans before grinding them can lead to a less messy process, a more flavorful brew, and significant savings for the coffee industry. So, the next time you’re about to grind coffee beans, give them a quick spritz and enjoy a noticeably better coffee experience.

post written by Eugene Nielsen

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