Descaling isn’t the most fun part of the coffee-making process, but it’s absolutely necessary for a well-working (and clean!) machine. Descaling is particularly important in single-serve machines, which, yes, includes Keurigs.
Most coffee machines need to be cleaned out once per month, either using a descaling solution or vinegar. Typically, this involves running the machine once with the cleaning solution and at least twice more to flush it. We’ll go through it step by step in just a second, but just to drive home how important this is...
For all of you out there who don’t seem to think your coffee maker needs to be cleaned, hold that thought until you know the names of the germs, mold, and bacteria housed in your machine.
Without thinking too deeply into it, it makes sense that you wouldn’t need to clean the coffee maker a ton. Super hot water should boil away anything, right? Not to mention, caffeine is naturally antimicrobial. Unfortunately, it doesn’t quite work that way.
Our minds always immediately turn to our basic understandings of buying any sort of technology item—the warranty always expires right before it breaks, manufacturers always err on the side of caution so they can shirk responsibility should issues arise, and, of course, they want to get you to buy more of their special cleaner. Usually, we’d agree, but this is not that.
We were nonbelievers, too, until one of our team members found mold growing in the water reservoir of their household Keurig and was unable to stomach using it for upwards of six months.
It’s not just special to some of us. A local news station went around Chicago and randomly asked to swab machines in 10 homes, which were then inspected by microbiologist Roman Golash at Loyola University. He found gram-positive strains of bacteria including staphylococcus, streptococcus, and bacillus cereus, along with e-coli.
Additionally, a study done in 2011 by the NSF International, a non-profit independent public health organization, showed very similar results, including that coffee machines had more germs than most other areas of the kitchen and bathroom.
Alright—do we have your attention now? Good. Let’s have a serious discussion about water, descaling, and what all of that actually means.
Hot and moist crevices are bacteria’s absolute favorite place to grow and the entire internal workings of your coffee machine is a hot, moist crevice that gets clogged by calcium and magnesium in water.
The calcium and magnesium form in layers called limescale—yes, the same chalky, off-white substance you can find on things like your showerhead or other places where metal and hot hard water meet.
If your first reaction was to use distilled water, which only has minute traces of these minerals, you wouldn’t necessarily be wrong, but it’s not quite the right solution, either. While it may prevent the buildup of limescale, it won’t give the result you want.
In a true twist of irony, the same minerals that are so detrimentally fatal to your coffee machine are the same ones that help bring out the most delicious of flavors in your mug of joe. Without calcium and magnesium taking up molecular space in your water, there’s simply too much room—the coffee over-extracts and results in that terrible bitter taste we all despise.
The Speciality Coffee Association (SCA) defines the perfect water for brewing to be: clean, as well as odor- and chlorine-free. Basically, if you drink it on a daily basis without concern, it’s likely the right stuff to make your coffee with.
To get technical, the alkalinity target is 40 ppm while the calcium hardness should be between 50-175 ppm CaCO3. If you’re not a scientist with the proper equipment to test this sort of thing, hard water run through something like a Brita Filter with gallon-plus capacity will serve you just fine to get a full pot of beautifully brewed coffee.
However, hard water creates limescale build up in your machine, so you absolutely must descale your machine on a regular basis. So how do you know when to descale?
There will be visible and audible indications that it’s time to descale. You likely won’t even notice them until they’re a supreme annoyance on your morning schedule. The first symptom will undoubtedly be a slow down in the roasting process—it’ll be especially noticeable in single-serve machines.
Eventually, it won’t brew the same amount of coffee. So, now, it’s taking longer and not provided you with enough of the caffeinated goodness you want. You’ll likely hear some hefty chugging sounds, too, as water struggles to get through the clogged pathways. Once you’ve noticed these symptoms, it’s likely far past time to descale your machine.
You’ll notice a difference in taste, a very unpleasant morning surprise. Some describe the taste as chalky or even a disgustingly sweet, acidic taste. But however your taste receptors register the anomaly, there’s nothing enjoyable about it. Once you’ve reached this state for long enough, there’s a low chance that you’ll be able to descale it with much success.
To avoid needing to throw out your coffee maker, a machine used daily should be descaled on a very regular schedule, between 1 to 3 months depending on manufacturer recommendation and usage. On top of totally bypassing the issues of an underperforming machine, this will also prolong the life of your coffee maker.
Luckily, there’s nothing complicated about descaling your machine, as complicated as the word “descaling” sounds.
To “descale” something means to remove the hard deposits formed by chemicals in water from something, typically a showerhead, pipes, kettle, or coffee maker. While it is a chemistry term, you don’t need a chemist to descale your machine.
Descaling is deceptively simple and takes less than fifteen minutes. Fifteen short minutes each month for a longer lifespan on your beloved coffee maker seems worth it to us! So, on to the real question: vinegar or descaling solution?
Everyone wants a definitive answer, but there really isn’t one. Both vinegar and descaling solutions work equally well when it comes to descaling. Some people say that the white vinegar leaves a lingering taste, but many also tout it as the ideal method to clear away limescale. Some manufacturers, like Mr. Coffee, solely recommend white vinegar to clean their machines.
Whether you’re looking for how to descale a traditional coffee pot, how to descale a Keurig, or even how to descale a Keurig 2.0, you can clean any machine with white vinegar using a simple “recipe.”
What You Need:
Take out any removable parts and clean them thoroughly. Clean the exterior of the machine and wipe out any visible parts inside.
Dump both the one-part white vinegar and two parts water into your machine’s water reservoir. Run your machine and discard what’s “brewed.” If you’re cleaning a single-serve machine, brew the largest cup available until the machine indicates it’s low on water. Discard whatever’s left in the reservoir.
Fill the water reservoir again, this time just with water. Run the machine as normal ad discard the “brew.” Again, if you’re cleaning a single-serve, brew the largest cup available until empty.
Repeat step two and then you’re done!
Some machines have a descaling or cleaning button/function. The machines will often pause, sometimes as long as 30 minutes, to hold the vinegar or descaling liquid inside the machine. In this case, make sure to read the directions.
If you’re skeptical, don’t like the smell of vinegar, or would just prefer to use a descaling solution, that’s also an option, obviously, albeit a slightly more costly one. Many come in 2-use bottles like Impressa Descaler, the Essential Values version, or this one from FreshFlow.
They don’t really say on the bottles, nor on their websites, but some options for descaling solutions include acetic acid, citric acid, glycolic acid, formic acid, phosphoric acid, sulfamic acid, and hydrochloric acid.
You likely recognize only one or two ingredients on that list, but you’ll note that they all say “acid.” You can also find homemade descaling recipes using things like lemon juice or using actual citric acid.
Back to the pre-made solutions, though. Keep in mind that some of them require you to use the descaling solution up to 3 times per descaling, so even if they come in a two-bottle kit, one use is half of the bottle, meaning that you need a bottle and a half for every descaling. If you opt for the Impressa Descaler, it recommends you go through the entire cleaning process three times each time you descale.
Just some food for thought.
The directions are the same for both the original Keurig and Keurig 2.0 machines. Keurig recommends its own descaling solution and has a particular process.
Shut off your machine and remove the reservoir from the machine. Clean it thoroughly, nooks and crannies and all. This is a recommended action for all machines.
Pour Keurig Descaling Solution into the reservoir. Fill the empty bottle with water and add that to the reservoir, as well.
Power the machine back on and brew the largest cup available on the machine says the water is low. After completing this, let the machine sit for 30 minutes, powered on.
Thoroughly clean the reservoir and fill with water. They then recommend you brew a minimum of 12 “cleansing cups” of just water.
This step-by-step instruction guide is the only Keurig-approved way to descale your machine, including the requirement to use their descaling solution.
At the end of the day, no matter how you decide to descale your machine, the only thing that’s tried and true is that it needs to be done on a consistent, regular schedule.
For machines that aren’t showing any severe symptoms of needing to be descaled, I’d personally recommend white vinegar once per month to keep everything working well. If your machine is really struggling, it might be worth investing in a descaling solution to get past the rough patch and then regularly cleaning to avoid machine breakdowns.
Whatever works for you, just make sure you’re taking care of your precious coffee machine. Happy caffeinating!
Hi! My name is Rachel Bean and I love coffee. Despite what it may seem like, my last name and deep love for a cup of black brew is a total coincidence. While I was informed at the wee age of 18 that majoring in coffee wasn't really an option (at least not the way I wanted to major in coffee) (i.e. drinking it day in and day out), I do have an MA and an MFA in Writing. I type words day in and day out, for both work as well as fun, and coffee is the magic bean juice that lets me do that. And that's pretty much me. Writing and coffee. Oh, and rescue dogs. Writing, coffee, and dogs. You get me.
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