Static and Coffee Grounds

Written by Pat C
Content Creator
Published on May 6, 2020
Pat is an espresso machine enthusiast with a passion for perfecting every shot. With years of hands-on experience testing espresso machines, coffee makers and everything in between, Pat provides detailed, no-nonsense reviews to help coffee lovers find the right fit.
Static and Coffee Grounds

One complaint we see a lot about grinders is that grounds can sometimes come out with a lot of static cling. This is certainly a pain, but how much is the grinder to blame for this clinginess? Read on to find out!

What is static electricity?

Static electricity occurs when there’s an imbalance of electric charge on a material. All materials are made of atoms that are, at rest, electrically neutral. This is due to a balance between positively charged protons and negatively charged electrons. When two materials come in contact, electrons can move from one material to the other. The result is an imbalance between protons and electrons. It’s a complex process that’s a little heavier than what we’ve got time for today, but the main cause of static in coffee grounds is friction. As you can probably guess, there’s a lot of friction inside of a grinder as the beans make their way from the hopper, into the grind chamber, through the burrs, and down the exit chute. All of this is exacerbated by dry air. This is why it can be a problem one day and not the next.

So what’s the solution?

The general solution for reducing static buildup is introducing more moisture. If your beans are clingy, you are probably seeing static buildup in other places as well. A humidifier can be a good step towards making the air in your kitchen less dry. This can provide benefits beyond just coffee grinding! Another option is to introduce a bit of moisture into the equation with some water drops in the bean hopper. This is a delicate balance because you don’t want to add too much water to the hopper or it’ll cause grounds to clump, but too little won’t have much effect on the static. It’s also possible that adding water won’t end up counteracting the static either. In the end, the best solution may be the simplest. A good hard thump on the grind chute and knocking your catch bin on the counter can knock grounds to the bottom. From there, giving the coffee a few minutes to settle before pouring into a filter can help the static dissipate.

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