One of the best things about owning a burr grinder is the ease of making fresh, delicious coffee. With the press of a button or the flip of a switch, your home fills with the intoxicating aroma of ground coffee which you sniff blissfully in anticipation of a fresh, hot cup to come. Any disruption to this process can be jarring, stressful, even traumatic. The last thing anybody wants is a worrisome noise coming out of that grinder instead of coffee!
If you’ve experienced that dreadful low humming noise, you know what I’m describing – the grinder has clogged. Setting aside the disappointment of not brewing delicious coffee for a moment, you’ve likely asked yourself “why did this happen?” and more importantly, “how do I make sure it never happens again?”
I’m here to tell you exactly that.
What is a clog, and what causes it?
A clog occurs when a grinder’s discharge chute is 
compacted with coffee. I won’t dive into the nitty-gritty details of grinder anatomy (I did that already in this previous post) but the long-and-short of it is that coffee is ground by the burrs, and then needs to move out of the burr chamber and into a receptacle. That process almost always involves a small “hallway” through which ground coffee must pass (unless you own a Sette, that is). That hallway is probably where a clog will form – coffee only has one direction to move in there.
This compacted coffee is most often the result of an over-filled catch bin. Our grinders are designed for on-demand grinding, not bulk. If the hopper is filled with coffee and the machine runs continuously, eventually the bin fills to capacity and coffee is backed up into the discharge chute.
Another clog culprit is grinding frozen or refrigerated beans. Moisture on these beans from condensation will make for gummy grinding, which quickly clogs a grinder!
Speaking of gummy grinding – flavored coffees are often delicious but are also covered in sticky, sugary flavoring that often stops a grinder in its tracks.
Sometimes, a damaged part can cause this problem. It’s called the paddle wheel, and its job is pushing ground coffee out from the burr chamber. If this part is broken, coffee has a hard time moving through the system, and builds up as the grinder keeps going. A common cause for damage to this part is grinding rice to clean the burrs. This is a common idea about grinders, but is actually a pretty bad practice, because rice is denser than roasted coffee and makes for extra strain on the paddle wheel.
How do I remove a clog?
If your grinder is clogged, it needs to be cleaned out. Here’s the catch, though – a regular cleaning won’t do the trick! Brushing out the fine teeth of your burrs is great for your machine, but it won’t remove a clog since the obstruction is hidden inside the discharge chute. Because the grinder is compacted with coffee, it has to be physically cleared of the obstruction.
The brush that came with your grinder is the best tool for this. Specifically, the handle of the brush can be bent 45 degrees and used to push compacted coffee out of the discharge chute.
This might seem a little confusing, so we made a video specifically about this process.
If you don’t have that brush anymore, don’t worry! Any stiff, narrow poking tool will do. A small hex wrench (like you get from IKEA) is another great tool for fixing this problem.
How do I avoid a clog?
Avoiding a clog is actually fairly simple: don’t grind too much coffee at once. Our grinders are intended for grinding just enough coffee for your next cup or pot, which is great for freshness and avoids over-filling the grounds bin! Our Encore and Virtuoso grinders have fill lines on their bins which make it easier for you to see how much coffee has been ground – and when it’s time to stop.
It can sometimes be tempting to take coffee that’s already ground and send it through the machine again to grind even finer. While eliminating waste is great, this practice will pretty quickly cause a clog. These grinders are designed specifically for whole coffee beans.
Also, avoid keeping your beans in the fridge or freezer. Proper coffee storage can have a big effect on freshness and flavor. An airtight container, away from direct sunlight, and kept at room temperature is ideal for storing your beans.
Speaking of freshness, we also recommend buying smaller quantities of coffee at a time. Although that big bag at Costco is a great deal, if it takes months to grind all of that coffee, you’ll end up grinding coffee that’s gone stale. Stale coffee can become softer, or less brittle, than fresh beans, and a burr grinder will have a harder time breaking it down. Not only does fresh coffee taste better, but it’s better for your grinder too! Most roasters offer 12oz or 1lb bags of beans, and we wholeheartedly recommend buying in that quantity for best results in your grinder and in your cup.
With just a little care and consideration when using your burr grinder, you can avoid the hassle of a clog. That way, nothing will stand between you and that fresh cup in the morning!