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Cleaning Mold From a Keurig Coffee Maker's Water Reservoir

I can hardly function without my morning brew, so I investigated how to keep my Keurig clean and mold-free.

Your Keurig coffee maker isn't any more likely to have mold issues than any other coffee maker machine. But it does need to be cleaned and kept dry between uses.

Your Keurig coffee maker isn't any more likely to have mold issues than any other coffee maker machine. But it does need to be cleaned and kept dry between uses.

Coffee has become an essential part of modern life. I can hardly function without my morning brew. Keurig coffee makers are popular home coffee makers because they brew single cups of gourmet coffee in just a few seconds. But in order to keep the Keurig functioning properly and the coffee tasting great, it is important to clean the machine from time to time. Here are some tips to help you get the most from your Keurig.

Signs That It's Time to Clean Your Coffee Maker

Here are the telltale signs that your coffee maker is overdue for cleaning:

  • mold (either visible scum or smell only)
  • slow drip
  • calcium buildup on parts
  • unusually bitter-tasting coffee
  • mold allergy symptoms (sneezing and headaches)

Did you know that routine cleanings will help ensure great-tasting coffee, coffee maker performance, and a germ-free machine? An uncleaned coffee maker can harbor mold and other harmful germs. A National Sanitation Foundation study found that kitchens were the “germiest” places in the home. The study went on to note that kitchen items, including coffee maker reservoirs, have higher germ counts than a bathroom doorknob or light switch. Yuck!

Are Keurig Coffee Makers More Likely to Have Mold Issues?

No. In 2014 an article published in an alternative health magazine claimed that Keurig machines were designed in such a way that mold is more likely to build up. This is not true. While Keurig machines can develop mold, this isn't unique to Keurig coffee makers. All brands can become moldy if not cared for and cleaned properly.

That bottle of white vinegar in your kitchen cabinet is the best product to clean a Keurig coffee maker resevoir.

That bottle of white vinegar in your kitchen cabinet is the best product to clean a Keurig coffee maker resevoir.

How to Clean Your Keurig Coffee Maker

Are Any Parts Dishwasher Safe?

The water reservoir of your Keurig may be dishwasher safe. Remove it and look for those words embossed on the outside or inside. If yours can be washed in the dishwasher, go ahead and run it through a cycle. While that's cleaning you can wash the other parts by hand.

Use White Vinegar or Baking Soda and a Toothbrush.

Keurigs and other coffee makers can get clogged with hard water buildup. This accumulation leads to poor performance. The best way to remove buildup is to flush it out with white vinegar or baking soda. This process is called "descaling."

  1. If your reservoir is not dishwasher safe, pour an equal mixture of white vinegar and water. Alternately, fill the reservoir with water and add 1/4 cup baking soda. in Let sit for a few minutes. Use a toothbrush or round-tipped brush to scrub around the inside and bottom. This will clean the reservoir and the water intake hole.
  2. Run this solution through the machine with no K-cup inserted. If your Keurig has never been cleaned or is badly clogged, you may need to repeat the process more than once.
  3. Once you have run the white vinegar solution through your machine, run plain water through three or four times to rinse all of the vinegar.
  4. NOTE: If your Keurig is not for single servings and has a large reservoir that is never empty, you will need to rinse the reservoir out or run many more plain water operations through your machine.
If any parts of your Keurig Mini are dishwasher safe, wash them that way and use white vinegar to clean other parts by hand.

If any parts of your Keurig Mini are dishwasher safe, wash them that way and use white vinegar to clean other parts by hand.

How to Care for Your Keurig Coffee Maker

Always Use a Clean Cup to Fill Your Machine.

Using a dirty cup can introduce bacteria and mold, which can affect the taste of your coffee and possibly impact your health.

Leave the Lid Open When Not in Use so the Reservoir Can Dry.

If you use a Keurig Mini or other single-serving coffee machine, consider leaving the reservoir lid open when not in use. This will allow the water tank to dry. A wet tank that is not used for a few days will is an ideal environment for mold, which would end up in your coffee the next time you use your machine.

Remove and Clean the Platform Tray for Mugs From Time to Time.

Excess water and coffee drain into this tray and can cause gunk to develop. If you use your Keurig often, this tray will likely contain standing liquid and mold. Use a damp cloth and some dish soap to wipe any water away.

Use Bottled Instead of Tap Water.

Bottled water has fewer minerals than tap water and will cause little or no buildup in your machine. Bottled water can be expensive, however. An affordable alternative is to use a water filter, which will remove most of the mineral content.

Wipe the Coffee Maker Dry After Use.

Use a paper towel to wipe the inside of your Keurig dry after use. Mold is less likely to develop in a dry environment.

Thanks for Reading!

I hope you found this article useful. What has worked for you? Which devices or parts are really tough to clean? Please share your tips and experiences in the comments section below.

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© 2011 Art Vandelay


Patricia L Libby on December 01, 2019:

I have a Keurig machine about 5 years old. Once a month I use dishwasher liquid (not dish soap DISHWASHER MACHINE LIQUID) to clean my machine.

I put hot water and dishwasher liquid in the tank and run it through until the water comes out clean. Then I will run about 6 tanks of clean cold water through it to make sure all the dishwasher liquid is out of it. It works so good.

I always remember to leave the front area and tank open when not in use to make sure it dries out inside

David on November 21, 2019:

I have a Mr. Coffee that got stuck because I used one of those "Fill your own K-Cups" with your own coffee and used too much. Ended up having to take the top of the hinged part that contains the tube and spike off. 2 seconds to clean it after that. About an 1+ hours to figure out that was what was needed.

If it ever happens again, I plan on taking a Dremel and cutting up the top. I'll cover the hole with inner tube rubber glued onto the plastic.

That's a 40+ year old trick that auto repair shops used sometimes 40+ years ago on Chevy Monzas with a V8 stuffed into them. You could either:

1. use multiple ratchet extensions to get some spark plugs out.

2. Loosen the engine mounts to jack up the engine.

3. Use a hole saw to cut a hole in the inner fender well to give you a direct shot to the spark plug. Then as I stated, a square of rubber inner tube glued to to the fender well.

Richard on July 22, 2018:

green film in is this by direct sunlight

BETH on February 20, 2018:

I just bought a Keurig 2.o second hand. I have run 2 vinegar solutions through it and at least 8 full tanks of water...I'm still getting debris. I've taken all parts and washed them, shot the inside with a sprayer.....I don't know what else to do.

Jack on November 02, 2017:

If you take the bottom off are the plastic corrugated tubes black? Could they have mold?

Richard Hurts on October 14, 2017:

What about killing the mold and bacteria in the Keurig? What about flushing with ammonia, alcohol, H2O2 or other’s. Ixyclean?

silentmessage13 on August 16, 2017:

if you use bleach it will only make the pink mold(same as in your tub) grow quicker. this is why vinegar is best. however if you do not run it threw every week and leave water lid and kcup lid open to dry your just going to keep getting it. the only way to actually clean it out is to replace parts completely or take it apart and spring clean the water valves and reservoir.

ceecee on April 02, 2017:

It looks like there is slimy mold in the bottom that I can not reach. I have done everything possible to clean and remove it but the slimy mold like substance remains. Now this is a worthless appliance taking up space in my kitchen.

Ken on November 14, 2016:

My B60 Keurig has interior water tank / boiler. Removal of this

boiler tank for inspection and cleaning would be really

nice, but alas - Keurig placed it inside a nearly Impregnable

fortress and built everything around it. When we "descale"

following the recommended procedure with white vinegar

or descaling solution, the solution of course fills this boiler

and cycles through it as you repeat the cup filling operation.

You were on the right track by turning the machine over

and shaking it.

Here is what I do (accomplish at your own risk):

1. unplug Keurig

2. remove exterior water tank, cup tray, etc.

3. turn Keurig upside down and smack it sharply on the bottom

SEVERAL times or until you break your wrist (or a nail~:)

4. Fill external reservoir with 50 / 50 filtered water + white

vinegar solution and run at least 4 (large) cup cycles.

5. after the last cup cycle, let the Keurig sit for 30+ minutes

to allow the vinegar / water solution to dissolve scale, calcium,

mold, etc. buildup inside the boiler tank, internal water pump,

solenoids, lines, etc.

6. empty and rinse the external tank with filtered (fresh) water

and fill it with filtered water.

7. run at least 6 large cup cycles to thoroughly flush all the internal

liquid bearing components (boiler tank, etc) - refill the external

tank as necessary (with filtered / fresh) water.

I have used the above procedure several times on two Keurig

machines to successfully restore normal flow (proper cup levels).

Call me one of those "`lesses" (careless, fearless, senseless), but

as long as the water is being properly heated I don't worry much

about bacteria. If I'm drinking bacteria, I rationalize that it is dead

bacteria (or at least scalded) and that helps me sleep at nite -

lest of course if I've had more Caffeine than I should have ~:)

Gail Mont on November 03, 2016:

There is an inside water reservoir which we cannot get to. I have turned my machine up side down and shook it, I can hear water moving about. How do we clean that...there has to be mold and bacteria there. Thanks for any suggestions

afry on June 03, 2016:

I have a single serve and cannot remove the water reservoir. I have run through over 6 cycles of vinegar (plus rinsing with water) and still have black specks. :( Any suggestions?

Carson collins on May 30, 2016:

Just got my keurig at a pawn shop didn't know it had a internel water don't know how long that water has been in the machine I think I'm going to throw it away and eat the $30.00 I payed for it

Dan on April 03, 2016:

My Keurig took forever to reload water... The issue was the screen filter at the bottom of the water tank... It took a long phillips head screwdriver to remove the screen.... soaked it in vinegar over night and took a soft hobby acid brush to it..... removed all the green slim and rinced it well... reinstalled it and it reloads the water quickly.... ran white vinegar thru it and good to go.... so if your Keurig takes forever to load water check the metal round screen for slime

Ken on August 11, 2015:

The water tank is dishwasher safe so it's OK to run it through a cleaning cycle.

Karin on June 14, 2015:

Remove the water tank use your kitchen sink sprayer hold the tank upside down and spray hot water with high pressure up into the tank. This removed all the mold in the filter and hard to reach places. Of course do this after cleaning with detergent.

ph on November 16, 2014:

I was told that even vinegar would not get rid of slime & mold in tubing, etc., other parts of a keyring.

Margie L on January 09, 2013:

What should you do if you are going to be gone for a few months. How would you drain the water or prepare it so there is no problem when you return?

Mt on August 02, 2012:


PatN on December 03, 2011:

Thanks for the help - we found it very useful. We get mold in our water reservoir occassionally and find it difficult to wipe the bottom clean - The white vinegar and leaving the lid open will help lots!

Jackie Lynnley from the beautiful south on April 02, 2011:

Sounds great, voted it up, great name (lol) welcome to hubs!


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