“They don’t make ’em like they used to.”
You’ve absolutely heard that phrase before, and it definitely applies to kitchen appliances.
If you own a Keurig brewer you probably spent over $100 on a piece of plastic that has far too large of an impact on your daily routine.
Or maybe that’s just me.
Unfortunately, Keurig brewers only come with a one-year warranty, which is less than reassuring given the cost of buying one.
If you read online reviews there are two big complaints that arise frequently:
- Clogging
- Inconsistent brew size
These issues can be delayed, avoided or even fixed with proper regular maintenance in a process called descaling.
In this article I’ll explain not only how to descale a Keurig coffee machine but also the science of descaling, in case you’re like me and want to know what’s happening.
What Is Descaling?
I’m a science nerd at heart–it’s one of the reasons brewing coffee is a huge passion of mine–so I want to do more than just show you how to descale a Keurig brewer.
I want to give you some detail around why you have to descale your brewer, but we'll save that for the end.
How to Descale a Keurig Brewer
There are two ways to descale a Keurig coffee maker:
- The Quick Way
- The Best Way
Click the links above to skip to each. But first, do these instructions work for every Keurig coffee maker? Yes, they do!
Pro Tip: Our Complete Guide to Every Keurig Model has links to the user manuals for every Keurig model made, which will give you instructions specific to the brewer you have.
The Quick Way
Total Time: 5 minutes
Pour one entire container of Keurig descaling solution into the water reservoir (making sure the water filter is removed), put a large mug or small bowl under the spout, and press the brew button without a K-cup in the machine. Once all of the descaling solution has run through the machine, fill the water reservoir with fresh water and run the Brew cycle to rinse.
That’s it.
The benefit of The Quick Way is that it’s quick. The con is that it reduces the descaling solution’s contact time with the coffee maker’s parts, which means you probably didn’t get as much limescale as you could have.
The Best Way
Total Time: 45 minutes (including 30-minute rest)
The Best Way requires more work breaking down your Keurig, to clean all its nooks and crannies, plus a 30-minute rest where the descaling solution goes to work on the limescale.
To fully clean and descale your Keurig, follow these 6 simple steps:
- Gather
- Disassemble
- Clean
- Descale
- Rinse
- Brew!
GDCDRB!
(I wish it made a better acronym.)
1. Gather
First, collect everything you’ll need to descale your Keurig:
- A descaling solution
- Water (both filtered and tap)
- Paperclip
- Non-abrasive cloth
- Dishwashing liquid
The descaling solution can be one of several different things depending on what you have handy:
- Pre-made descaling solution
- White vinegar
- Citric acid
2. Disassemble
Once you’ve gathered everything above, it’s time to disassemble the brewer and give it a good cleaning.
The image above shows all of the features for the Keurig K70/K75 brewer, most of which are standard across almost every Keurig model.
No, this isn’t technically part of the descaling process–for that skip to step 4 –but keeping every component of your Keurig brewer clean will ensure it works better for longer.
Pretty much every Keurig model has the same removable parts:
- Water reservoir
- Drip tray
- Pod assembly (where you insert the pod)
Take it all apart.
3. Clean
With dish soap, warm tap water, and a non-abrasive cloth, clean each component you’ve removed from the brewer.
This is also where the paperclip comes into play: use it to clean the entry and exit needles inside the brewer’s pod compartment. Make sure you unplug the brewer first.
For a really good cleaning, you may also want to use a mixture of equal parts vinegar and warm water to wash anything that actually comes in contact with coffee, such as the pod assembly (items G and H in the image above) or the carafe (should you have a Keurig 2.0 K200 series brewer or higher).
Why this extra step?
When you brew a great cup of coffee, what you’re really doing is extracting oils from the coffee beans to provide the flavor, richness and mouthfeel you love.
Oh, those lovely oils!
Those oils also have a dark side. Exposed to air, they can oxidize and turn rancid. This is not the flavor you love. In fact, if you’ve ever had a cup of coffee that just tastes…old, it’s probably from rancid, oxidized oils.
So do your taste buds a favor and remove that rancid flavor!
(Rhyme 100% intended.)
If you want to know more about the science of oil oxidation, this is a great resource.
When you’re done cleaning, reassemble your brewer.
4. Descale
This is where the magic happens.
Step 1: You’ll have to mix up your descaling solution, so grab your descaling agent of choice–vinegar, citric acid, or a pre-mixed solution–and add it to the proper volume of water. Your goal is to fill the reservoir to the MAX FILL line with a properly mixed descaling solution of the correct concentration.
Depending on which descaling agent you’re using, the ratios of agent-to-water are different:
- Vinegar: 1 part vinegar to 1 part water
- Citric acid: 20 parts citric acid to 1 part water
- Pre-mixed solution: 1 part pre-mixed solution to 1 part water (but check your specific agent’s bottle to make sure)
Note: If you have a water filter in your water reservoir, remove it before adding the descaling solution.
Step 2: With the descaling solution already mixed in your brewer’s water reservoir, grab a large mug and place it on the drip tray.
Step 3: Run the largest brew setting possible by lifting and lowering the handle without inserting a pod. Repeat this process at least two more times, or until your brewer indicates it needs more water.
Step 4: Let the brewer rest. The descaling solution has circulated through the brewer’s internal parts and needs some time to do its thing. I’ve seen Keurig manuals instruct you to let the brewer sit for up to 4 hours, but 30 minutes will do the trick.
Your brewer is now descaled, but you aren’t ready to brew a fresh cup of coffee.
5. Rinse
Empty the water reservoir of any remaining descaling solution and give it another quick clean with dish soap and a non-abrasive cloth.
Next, reinsert your water filter (if applicable) and refill to the MAX FILL line with filtered water. Run as many brews back-to-back as you can until the brewer indicates it’s time to add more water.
When that happens you’re finally ready to…
6. Brew!
Congratulations! Your Keurig brewer is ready for use. And because you cleaned so thoroughly, the next cup should be one of the better servings you’ve had in a while.
It’s possible your first brew may taste a little like the descaling solution, especially if you used more descaling agent than instructed. If this is the case just discard the brewed coffee and repeat the rinsing process another time.
The Science Stuff
Let’s Talk About Limescale
Descaling is the process of removing limescale, a chalky build-up primarily comprised of calcium carbonate (CaCO3). For us mortals out there, it’s also called chalk and is formed from the skeletal remains of ancient sea creatures.
Yes, you’re removing sea creature skeletons from your brewer.
Water used for brewing has various concentrations of dissolved sea creatures calcium carbonate, plus other dissolved minerals. Over time through the repeated heating and cooling of the brewing process, calcium carbonate slowly precipitates (or falls) out of solution, meaning it’s no longer dissolved in the water. Instead, it deposits itself onto the inner workings of your brewer as limescale.
How quickly this happens depends on how much dissolved calcium carbonate exists in the water you use.
Water Hardness
You’ve probably heard of hard and soft water. Water is water, so how can it be hard or soft?
This hardness refers to how much calcium carbonate (and to a lesser degree magnesium carbonate) is dissolved in your water, otherwise known as the concentration.
Concentrations can be measured in many different ways:
- Milligrams per liter
- Millimoles per liter
- Grains per gallon
- And more!
But one of the most common measurements is parts per million (ppm)
As the name implies, parts per million represents how many molecules out of one million are of the ion we care about, in this case dissolved calcium (Ca2+) and magnesium (Mg2+) ions.
Chemistry Class: An ion is a charged molecule, noted by the “2+” in the calcium and magnesium ions above, and represents the relative imbalance of positively charged protons and negatively charged electrons. Ca2+ means the calcium ion has two more positively charged protons in its nucleus than it has negatively charged electrons encircling the nucleus.
Water hardness is classified according to the following ppm concentrations:
- Soft: Less than 60 ppm
- Moderately hard: 60-120 ppm
- Hard: 120-180 ppm
- Very hard: Greater than 180 ppm
So if you ever hear someone say they have hard water, now you can say this:
“Wow, I didn’t know you had between 120-180 parts per million of dissolved calcium and magnesium in your water. How interesting!”
Why does water hardness matter?
Harder water equals more rapid limescale accumulation, which equals more frequent descaling.
Can’t I Just Use a Water Filter?
Keurig recommends you use a water filter, and you should do as they say. These water filters use ion exchange to reduce the concentrations of dissolved calcium and magnesium, reducing the water’s hardness.
However, they are unable to remove all of the dissolved calcium and magnesium.
In addition to the calcium carbonate and magnesium carbonate compounds we’ve been discussing, your water also has dissolved calcium and magnesium sulfates and chlorides. These molecules contribute to the water’s permanent hardness, which water filters can’t remove.
There’s a lot of chemical names coming at you. Here’s a table, in case you were curious:
| Anion | Calcium (Ca2+) | Magnesium(Mg2+) | Temporary or Permanent | Removed by Water Filter | Contributes to Limescale? |
|---|---|---|---|---|---|
| Carbonate | CaCO3 | MgCO3 | Temporary | Yes | Yes |
| Sulfate | CaSO4 | MgSO4 | Permanent | No | Yes |
| Chloride | CaCl2 | MgCl2 | Permanent | No | Yes |
An Anion is just a negatively charged ion. Carbonate (CaCO3 2-) is an ion with a negative charge, which makes it an Anion. Conversely, an ion with a positive charge such as calcium (Ca2+) is called a Cation.
To remove permanent hardness you need to add washing soda, which will bind to the calcium and magnesium ions you wish to remove and precipitate them out of solution. If you’re curious, you can read the chemistry behind that process here.
The take-home message: There will always be some concentration of the limescale-creating calcium and magnesium ions.
What Is a Home Barista to Do?!
A home barista shall descale!
Basically, you need to find a way to remove the scale-like, chalky build-up from your brewer’s inner workings. That’s where the descaling process comes in.
In this process you use a descaling agent, generally an acid such as acetic acid (C2H4O2, otherwise known as vinegar) or citric acid (C6H8O7, the stuff in your oranges and lemons).
These acids dissolve the limescale and flush it out of your brewer.
Just like that, no more limescale!
