Minimizing Static in Burr Grinders | Cook's Illustrated

Minimizing Static in Burr Grinders

By Cook's Illustrated Published March 2014

When emptying the grind chamber of burr-style coffee grinders, ground coffee will often stick to the chamber and fly all over the counter. Are there solutions to this problem?

The problem is static electricity. When beans pass through the grinding mechanism, they pick up an electrical charge that causes the ground coffee to “jump” out of the grinder or stick stubbornly to the sides of the container that captures the ground coffee (often called the grind chamber). This problem becomes worse when the chamber is made of plastic; it’s a very poor conductor of electrical charge, so these particular grind chambers don’t encourage the electricity in the ground coffee to dissipate quickly.

An online search turned up several possible fixes, but most of them didn’t work. Since dry conditions encourage static buildup, water seemed like a logical antidote. But adding a couple of drops of water to the beans before grinding made no difference, and misting the chamber with water prevented the jumping problem but exacerbated sticking. Many coffee fans suggest running a strip of aluminum foil from the inside of the plastic container to the outside to provide an escape route for the static, but this not only was ineffective but also trapped grinds behind the foil, making it messy to empty them into our coffee filter. We were intrigued by one suggestion: stirring the ground coffee with a metal fork to “gather” the electricity before lifting the lid. We found that a fork certainly gathered the static—as well as an abundance of the ground coffee with it. We even flirted with the suggestion of running a copper wire from the base of the grind chamber to the outside of the machine but ultimately rejected it since it required drilling a hole in our machine.

In the end, the best solution was the simplest: Give the static time to dissipate on its own. For medium-grind coffee (appropriate for a regular drip coffee maker), grind the coffee, wait for 5 minutes, and then remove the grind chamber from the machine. Rap the chamber firmly on the counter before opening the lid to send any stray grinds to the bottom of the container with the others. For finer grinds like espresso, add a few minutes to the waiting period; for coarser grinds for a French press, subtract a few minutes.