Cleaning and descaling a Keurig machine is good for your coffee and your peace of mind. Most water sources will eventually leave mineral deposits called scaling inside the machine, building up until they affect the taste of the coffee and the operation of the machine, especially when the block water passages.
Cleaning is not a difficult job, but it does require adding one more task to your already busy day, and even though you think of coffee every morning, you probably will have to remember to clean the machine sometime in the evening.
Keurig machines spoil us. Remember the process of grinding and measuring coffee, putting a filter in the basket, adding water and waiting for the brewing process to fill the four- to twelve-cup carafe? Now, we open the unit, remove any old K-cup, and put in a new one, close the unit, and press "brew" for our own cupful. They do need occasional cleaning, though.
Most water sources carry some minerals which are left behind during the brewing process. Steam leaves moisture, and a bit of the pod contents tends to lodge in the unit as well. On these surfaces, mold and bacteria may grow, providing another reason for thorough cleaning from time to time.
When we make coffee the traditional way, it's obvious that someone needs to clean up after us. With K-cups and the Keurig machine, it can seem like we're brewing in a sterile laboratory with nothing to clean up. This can lead us to forget that we need to do a thorough cleaning of the machine and the area or to put it off because we don't see any evidence of need.
In most homes, it seems, people dash out the door in the morning with their cup of coffee in hand. There's no time to clean the machine then, but it might be a good time for a quick soapy cleaning of the outside, maybe every Friday morning or every other week.
What about the Keurig machine in the break room? It serves a lot more people, so yes, it should be cleaned more often. Volunteers don't usually step up for this kind of job and too often it falls to a person with an administrative role who is plenty busy already. Consider publishing a schedule of cleanings and keeping an eye on whether the scheduled cleanings get completed and checked off. It's important for everyone's health and for tasty coffee.
There's a theory that a busy machine keeps itself clean, especially a commercial machine such as those baristas use. Don't be fooled; someone has to clean any machine which brews coffee. Steam might kill some bacteria, but you need to get cleaning materials into every nook and cranny where water and coffee flow to be absolutely sure.
On stainless steel or plastic surfaces, a clean machine is one which sparkles or otherwise reflects light without interruptions. When scaling or growths occur, you'll see disruptions in that sparkling surface and even be able to rub off a bit or mineral deposits or organic matter. Hopefully, you clean often enough to avoid this unsavory scenario, but if it does happen, then it's time to push cleaning a lot higher on your priorities list.
Don't overfocus and just perform a Keurig machine cleaning by itself. Under the unit and behind it are probably a lot more nasties similar to the ones inside the machine, the result of spills and overflows. Pull out the machine and coffee supplies and take the time to clean -- you'll be so glad you did.
For the machine cleaning, you have a choice of white vinegar or Keurig cleaning solution. You can get both in most grocery stores and many other retail locations. Disassemble and clean the parts including the two K-cup piercing needles about every month and descale every three to six months or when the light comes on or your cup doesn't fill. To descale, add 10 ounces of white vinegar and brew it into a durable cup. Do the same for 10 ounces of water, then rinse the reservoir, fill it and keep brewing until it's empty. Using a descaling solution is about the same, but check the label for exact instructions.
Double-check that you performed that last cleaning step, running about 12 brew cycles to empty the freshly-filled water reservoir. Then you're ready to enjoy a coffee or your favorite beverage from a clean machine. Remember to plan ahead and keep your preferred descaling liquid to use the next time you clean your Keurig machine.