The symptoms of dreaded Keurig scale 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.
Scale precipitates out of hard water—water with a lot of minerals in it—and then 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.
Step 1: Get your Keurig emptied and ready
Clear out all the coffee and empty the Keurig. Clear out a nearby sink to create plenty of room, too. Pour whatever water is left in the reservoir down the drain, and make sure there are no 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.
Step 2: Prepare your descaling agent
Now you need an acidic descaler to run through your brewer so it can break apart the scale. 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 $13, which lasts for a single use. It’s an easy option that doesn’t require much effort, and by all accounts it does get 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 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. The only downside worth noting is that you 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 the rest of the day.
With 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 around half vinegar and half water, possibly even more vinegar for a really tough descaling job.
Step 3: Run all your descaler through the Keurig
Arrange your Keurig settings for a normal, full cup of coffee — you can go larger if you have a thermos nearby, but a mug typically works best (again, make sure there’s no K-cup inside). Run the descaling mix 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 acidic vinegar about now, but keep going until the reservoir is empty.
By the end of the reservoir, 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 another tank with more solution and repeating the whole process, just to make sure.
Step 4: Flush the Keurig with fresh water
Leave the Keurig to sit for a bit while still on, 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 away. Once the first reservoir of water is empty, fill it up again and continue doing the same thing. It will take a least two full tanks of water to flush out your Keurig, so prepare to get rid of a lot of water.
At this point, you may want to do a taste test to see if you can taste any of the descaler remaining in the water. If you can, don’t be afraid to flush out a couple more reservoirs of water, as the flushing can never be too thorough.
Final tip: Preventing scale
Generally, scale forms more easily from tap water. That’s why Keurig suggests you use filtered or bottled water when possible 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.