The dreaded symptoms of scaling on your Keurig are unmistakable: Slower pours, settings that no longer work, stinky build-up, and a half cup of coffee when you really needed that full cup.
Scaling occurs when hard deposits in water — water with a lot of minerals in it — attaches to the inside of the Keurig, gradually clogging up its tubes (the same thing can happen to your plumbing, too). More advanced Keurigs will often tell you when it is time to descale, but it’s generally a good idea to do it every six months or so if you use regular tap water. Here’s how to descale a Keurig when the time comes.
Note: This is about descaling specifically. If you want to give a dirty Keurig a thorough cleaning, check out our guide on how to do that as well.
Empty the Keurig, then clear out a nearby sink to create plenty of room. Pour whatever water is left in the reservoir down the drain, and make sure there are no K-cups left inside the brewer. Find a large mug to use for draining, and make sure no one is going to need their coffee fix for the next couple of hours.
Now you need an acidic descaler to run through your brewer so it can break apart the calcium deposits. There are two popular descaling choices, both with pros and cons.
Keurig Descaling Solution: Keurig sells its own descaling solution that you can buy for around $7 to $15, which lasts for a single use. It’s an easy option that doesn’t require much effort, and by all accounts gets rid of scale. But if you read the reviews on both Keurig’s own product page (where it scores only three stars) and on Amazon, you’ll find that the solution tends to have a citrusy odor that can be very hard to get rid of, and may even affect the taste of your coffee for days to come.
White vinegar: White vinegar is very cheap, readily available, and works great on scale. You’ll need at least several cups for a good cleansing, which means you may have to go out and buy some more specifically for this project. Also, it is vinegar, which means your kitchen or break room may reek of that vinegar smell for a little while.
If you’re using the Keurig solution, you will want to empty the entire bottle into the reservoir, and then fill the rest with clean water. For white vinegar, you want your reservoir to be filled with half vinegar and half water — possibly even more vinegar than water for a really tough descaling job.
Set your Keurig for a normal, full cup of coffee — you can go larger if you have a thermos nearby, but a mug typically works best. (And again, make sure there’s no K-cup inside.) Run the descaling solution through and wait for the cup to fill.
If your Keurig has a bad scale problem, it may not be able to fill up a full cup even on the right settings. That’s okay, the solution takes a little time to work. Continue filling cup after cup and pouring them down the drain. If you used the white vinegar solution, the room is really going to start smelling like vinegar, but hang in there and keep going until the reservoir is empty.
By the end, the water should be pouring more smoothly and filling up cups with a bit more ease. If you don’t notice any improvement at all, you may want to fill the reservoir with more solution and repeat the whole process, just to make sure.
Leave the Keurig to sit (still powered on) for a while, around 30 minutes. This gives the acid time to break down remaining scale inside the brewer. Now, carefully clean the reservoir, and wipe down the inside to remove all traces of the vinegar/solution. When finished, fill up the reservoir with clean, fresh water. It’s time to flush out all of the descaling solution from the system.
Once again, set the Keurig for a full cup and start running cup after cup of water through the brewer, dumping each. Once the reservoir of water is empty, fill it up again and continue doing the same thing. It will take a least two full reservoirs of water to flush out your Keurig, so prepare to get rid of a lot of water.
At this point, you may want to perform a taste test to see if you can taste any of the descaler remaining in the water. Don’t be afraid to flush it out a couple of more times, as the flushing can never be too thorough.
Generally, scale forms more easily from tap water. That’s why Keurig suggests you use filtered or bottled water to fill up the brewer and help keep scale problems to a minimum. Bottled water is a pricey option, but you may want to consider buying a simple water filter to use solely for your Keurig, if scale has been an ongoing issue for you.