Adding just a few droplets of water before grinding coffee helps reduce static electricity. When beans are ground dry, friction creates static, causing grounds to cling to your grinder’s surfaces and even fly out when you open the container. This makes dosing messy and inconsistent.
Spraying beans solves that.
What happens when you spray the beans?
- Less static = cleaner grinder and workspace
- Grounds fall evenly into the portafilter or container
- More accurate doses for brewing
- No clumps or flying grounds
The water keeps the particles from repelling each other, making for a smoother grind and easier cleanup.
The Ross Droplet Technique (RDT)
This method, named after coffee enthusiast David Ross, is the most popular way to apply water to your beans before grinding. It’s as simple as it sounds.
How to do it:
- Measure your beans.
- Lightly mist with a spray bottle—just 1–2 spritzes for 18–20g of beans.
- Shake the beans to distribute the moisture.
- Grind as usual.
That’s it! No need to soak the beans—just a touch of water does the trick.
Does It Change the Taste?
Yes—especially for espresso and other fine grind methods.
By reducing static and clumping, RDT ensures a more uniform grind. That translates to more consistent extraction when brewing, which can highlight the subtle flavors in your beans. For high-end beans or single-origin coffees, this difference can be noticeable.
But don’t worry—it doesn’t add any water to your final cup. The small amount used evaporates or gets absorbed quickly, so you won’t be brewing wet beans.
Tools to Use
You don’t need expensive gear for this trick. Most people use:
- A small spray bottle or misting bottle
- Digital scale to measure beans
- Glass or ceramic bowl to shake/mix beans
- Your favorite grinder (manual or electric)
Bonus tip: Keep your spray bottle filled with filtered water to avoid mineral buildup on your grinder.
When It’s Most Helpful
Spraying coffee beans is most useful when:
- You grind for espresso (fine grind)
- You use light roasted beans (they’re more static-prone)
- You’re using a single-dose grinder
- You want to avoid wasting grounds stuck in the grinder
The Takeaway: Moisture Meets Mastery
While it might seem like a quirky barista habit, spraying coffee beans before grinding is rooted in simple science. A light mist can help you avoid static messes, improve grind consistency, and even elevate the flavor of your final cup.
So next time you reach for your grinder, give your beans a little spritz. It’s the easiest upgrade your coffee routine didn’t know it needed.