April 20, 2024


Cooking Is My World

How to Clean a Coffee Grinder

How to Clean a Coffee Grinder

I can guarantee that not enough people are cleaning their coffee grinders. 

And that’s ok! Perhaps you’re even reading this now and thinking, “I’m supposed to clean my grinder?” But coffee grinders are mysterious machines: with a click or a push of a button, they magically take beautiful whole beans and make them into uniform particle sizes that let you extract coffee’s wonderfulness.

Yes, this feels a little fantastical, but in our coffee grinder review, we talked to a handful of baristas and they echoed a piece of advice I myself have told hundreds of coffee drinkers: a good grinder is perhaps the single-most important piece of coffee brewing equipment you can buy. 

You can make more affordable choices with almost everything else in your home coffee setups, but investing in a good burr grinder is the key to a consistently brewed cup of coffee. As we explain in our review, a burr grinder evenly breaks down coffee into small, uniform particles, while a blade grinder is like taking a knife to a carrot and chopping haphazardly. A burr grinder’s that important! 

And after you’ve bought one, you want to treat your investment piece with love and care. But don’t go and start taking apart your grinder yet. Every machine is different, and there are two methods to cleaning your precious bean chopper (that’ll catch on as a cool nickname for grinders, right?). The first method involves using a dedicated grinder cleaner and can be used for most automatic grinders (the majority of the machines we covered in our coffee grinder guide) and the second is slightly more in-depth. So, I decided to provide a step-by-step guide on how to take apart and clean the Baratza Virtuoso+, the winner of our grinder review, to explain it.

Why Clean Your Grinder? 

Serious Eats / Ashley Rodriguez

As coffee moves through a grinder, oils and other particles will eventually get stuck to the interior. Over time, coffee oils go rancid, so the longer they’re allowed to stay and accumulate on your machinery, the less appealing your coffee will start to taste. If you’re drinking coffee and notice an oily finish or a bad taste at the back of your tongue you can’t quite identify, that’s usually a sign it’s time to clean. 

Serious Eats / Ashley Rodriguez

Cleaning your grinder is meant to remove coffee oils and discard old coffee grounds and particles that get stuck to your equipment over time. Most grinders designed for home use come with a brush or even grinder cleaner to use on your machine periodically, but you can grab any brush (as long as it won’t scratch the burrs, but they can withstand a small wire brush, which is what comes with most machines). 

If you don’t clean your grinder, the first thing you’ll notice is that rancid taste, which will get worse over time. But eventually, grinders that continue to collect oils and old grounds can clog or slow down the speed of your burrs. Also, random bits of coffee beans can end up in weird places in your grinder, so it’s important to both regularly clean with a grinder cleaner (that’ll help pick up the oils and other stuff that gets stuck to the burrs) and take the grinder apart (to get out any loose bits). 

I, of course, have long lost the wire brush that came with my original Baratza grinder, so I grabbed a soft brush from one grinder and a wire brush from a different grinder (this is the kind of house I live in) to clean my machine. 

How to Clean Your Grinder

Grinder cleaning happens two ways: one, by using a designated product to run through the grinder; and two, through taking the grinder apart. 

In general, I recommend using a grinder cleaner every four to six weeks, and then taking apart your grinder every other month, but this really depends on how often you’re brewing coffee at home and what type of coffee you’re using. The schedule I laid out is for someone brewing about a pot everyday and using their grinder once daily. According to the Barazta website, darker roast coffees have more oils and will leave more residue on your burrs, so you might want to use grinder cleaner more often, but perhaps stick to an every other month cycle for taking apart the machine. 

Method #1 — Coffee Grinder Cleaner

Serious Eats / Ashley Rodriguez

Grinders are tricky to clean for a lot of reasons. “Due to the fact that a coffee grinder sits atop an exposed electric motor, it cannot be cleaned with detergent and water, as this would damage the components,” writes Joshua Dick in his book, “Grow Like a Lobster.” Dick was the CEO of Urnex, a coffee cleaning equipment company based in New York, and noticed that there weren’t very many good options to clean a coffee grinder. “Historically,” he writes, “people have ground rice as a way to dislodge coffee oil residue from the internal cutting teeth, but this practice risks destroying a grinder in a number of ways.” 

At a coffee trade show, he met Nils Erichsen, the CEO of a then-small German coffee grinding company called Mahlkönig, and they decided to work together to develop a coffee grinder cleaner that didn’t require users to take apart the machine. “[With] a new friend who had access to a limitless supply of coffee grinders (since I broke quite a few during product development), I set out to come up with a grinder cleaner.” 

“In building Urnex, I was determined to help customers make better tasting coffee by finding ways to clean away old coffee residue from any part of the brewing process,” he wrote to me in a follow-up email. “When I started to learn about grinders, I soon realized that this was an often neglected part of the system. The goal was to develop something that was chemical-free, edible, and did not require water as a rinse. After about a year of development work and many more years of patent filings, we figured it out.” 

Urnex Grindz canister on white background

Also available at Walmart; price at time of publish is $28.

In 2005, Urnex (full disclosure: I do social media work for Urnex’s Instagram account) filed a patent for Grindz and started bringing the product to coffee shows. “I will never forget the first SCAA [Specialty Coffee Association of America] show where Grindz was launched. It was an instant success!” Dick says. “The concept was incredibly well received. In sharing the idea and demonstrating the product I saw peoples’ eyes light up as if we had just solved a problem that they knew they had been ignoring for too long. For the first few months or even a year production struggled around the clock to keep pace with demand.”

Serious Eats / Ashley Rodriguez

Grindz works by mimicking the shape of coffee beans and using food-safe ingredients to attach to coffee oils and residue. “The coffee bean shaped tablets fit perfectly into a grinder chamber and all ingredients were selected both for their cleaning and scouring abilities as well as their edibility,” Dick says. 

Serious Eats / Ashley Rodriguez

For this tutorial, I used Grindz, but you could use another coffee grinder cleaner if you’d like—just make sure your product is designed to clean grinders. Grinder cleaners couldn’t be any easier to use: measure however much you need (for Grindz, it’s between 35-40 grams, or about 1/4-cup for an at-home grinder), pour it in the hopper (the V-shaped top of the grinder), and grind like you would coffee. I recommend you grind a “burner” batch of coffee through the grinder just to remove any remaining cleaner, but all the ingredients in most grinder cleaners are food-safe (just check the label to make sure). 

The nice thing about this method is that you can do it as often as you’d like. I’ve seen experts recommend anywhere between once a week to once a month, but it really depends on how often you use your grinder and how much you’ll notice the difference in taste and quality of coffee brewed on clean burrs versus slightly dirtier ones. A fun experiment to do at home is to wait a few weeks, grind and brew coffee, then clean the grinder. Brew the same beans using freshly-ground beans on a newly-cleaned grinder, and see if you can detect the difference. You might notice the difference in the aftertaste (since grinder cleaners pick up old coffee oils) and in the clarity of flavors—a better-performing grinder should be able to grind coffee more consistently, which means you’ll be able to get more flavor clarity since the coffee is more evenly ground.

Method #2 — Take Apart The Grinder   

Serious Eats / Ashley Rodriguez

One of the reasons that Grindz was such a big deal when it came to market was that taking apart a grinder—especially taking apart the burrs, which are often delicately screwed and threaded into a grinder—is really time-consuming and it’s easy to break and lose pieces. When I was a wholesale coffee trainer in San Francisco, CA, my absolute nightmare was that I’d have to take apart a grinder and that I’d strip the threads and break the machine. 

“Not only were those few people who actually tried to clean their grinders stripping threads, they were misplacing screws, damaging outer cases, and wasting a lot of time both reassembling things and recalibrating their grind profiles,” Dick says. “Many big retail chains had been allocating as much as 30 minutes per store per week to clean grinders by opening and brushing.” 

Luckily, we’re not dealing with commercial equipment, but do check to see how your grinder is assembled before taking it apart. You can look at the manual or email the manufacturer to find out more information, but please do this before you take the machine apart. Missing a thread trying to reassemble the machine will render it useless until you can get a proper technician to fix it. 

Many at-home grinders, however, are designed to be taken apart easily, particularly those made by Baratza. In our grinder review, we recommended five different models of grinders—two of them are from Baratza. In researching for this article, I looked to see if there were any major differences between the Encore (one of their most popular models) and my Virtuoso, and I saw that the builds were virtually the same, so you can use this guide for either machine—you can also look at videos made by Baratza if you’d like someone to gently talk you through the process. I watched a video on cleaning three times before I went in just to make sure I was doing it right. 

Again, a quick note: this guide is primarily for the Baratza Encore and Virtuoso. If you have a different Baratza grinder, go to their YouTube channel to learn more about your specific grinder (many of Baratza’s grinders follow the same easy principles with pop-out pieces and intuitive builds, but the pieces are slightly different so it’s helpful to visually see someone else take apart the grinder first before you dive in). If you have a totally different grinder, read your manual, reach out to the manufacturer, or do a google search for video guides from trusted coffee experts. DO NOT TAKE APART YOUR GRINDER WITHOUT CONSULTING A GUIDE. 

The first step in cleaning your grinder is to empty out all the coffee beans. I usually don’t leave coffee in my hopper (I weigh out coffee every morning and then dose exactly what I need), but if you have any coffee in there, turn the grinder over and empty it out in a container. 

Next, grind out anything that’s left in the hopper. Even though you just poured out all those beans, there’s likely some still hanging around the very bottom and stuck in the burrs as well. Do this by pressing the grind button and letting it run until you hear no beans being ground. 

Now, unplug your grinder (safety first!), and remove both the hopper and the grounds bin. The grounds bin should be easy—you’ve probably already removed it before since that’s where the ground coffee comes out—but the hopper needs to be turned to the coarsest grind setting (the direction where the numbers get bigger, and you’ll see a little arrow indicating you’ve reached your mark). You can clean both of these pieces—and only these pieces—with soap and water. 

Serious Eats / Ashley Rodriguez

Next, take out the gasket, which is a black plastic ring. It should come out just by lifting up. Then lift up the removable section of the burrs (these are conical burrs, meaning they have a cone-shaped middle piece and an outer ring—you’re removing the outer ring). You can do this by lifting up from the two tabs sticking out. You’ll notice one of them is red—this is important later. 

Cleaning the gasket is easy, but you want to be soft and avoid stretching or breaking it. I’ll take a paper towel or microfiber cloth and just rub off any old coffee grounds. With the burrs, I’ll take that brush, and really concentrate on trying to get grounds out of the small, sharp “teeth” of the burrs by moving in an up and down direction. I like to do the ring part of the burr first, making sure to clean around the o-ring, or the plastic piece that encases the metal burr, before going in on the cone part. After I clean the cone part, I’ll turn the grinder over to pat out any loose grounds. 

Serious Eats / Ashley Rodriguez

Then you’ll want to use the brush to clean the grinding chute, or the little opening towards the bottom where ground coffee comes out. There’s no method to this: just get in there and try to loosen or shake out any grounds, and feel free to give the grinder a knock or two to loosen things up. And as you’re doing all this, you’ll likely notice that your burrs will never be perfectly clean. That’s fine: they will never be as pristine as the day you got them. You’ll have to decide when you’re done brushing off the grinders. If you want to get wild, you can buy a can of compressed air and knock out all those last little particles, but that’s not required. 

Remember that red tab? To put the grinder back together, take the ring part of the burr and line up the red tab with a red line in the body of the grinder. You can simply drop it in—you don’t need to click or lock it into place. Then put the gasket it (it has two indents to line up with the tabs). Then take your hopper, and find the side that has a silver line: line this up with the arrow towards the coarsest grind setting, push down, and rotate back to your original grind setting. And that’s it! 

Phew! You deserve a coffee now. And with clean burrs, it’s gonna taste awesome.


Can I use rice to clean my grinder? 

You could, but you shouldn’t. Rice is hard and brittle, so it can chip or damage the burrs, which are the bread and butter of your grinder. Coffee grinder cleaners now are designed to be soft enough to not damage your machine. 

Why can’t I use soap on my burrs? 

Most burrs on burr grinders are made from high-carbon steel, which helps them maintain their sharpness over long periods of time, but means they can rust if exposed to water. 

Do coffee grinder burrs get dull over time? 

Yes, and eventually you’ll want to replace them, but the question of when really depends on how often you’re using your burrs. Brands like Baratza will do that for you, or you can order one yourself and look up their tutorial for installing a new set of burrs. 

Do I need to clean my manual hand grinder? 

Yes. Like automatic burr grinders, manual grinders get dirty and their burrs need to be cleaned. You can run a dose of Grindz through your manual grinder just as you would normally, but consult your user manual before you begin taking things apart.