Can You Put Milk in a Keurig?

If you need a latte or hot chocolate, you put milk in a Keurig water tank instead of water. However, it can be a disastrously bad idea. Read on to find out why.

Keurig machine - put milk in a keurig
Never put a milk in your Keurig water tank

Now that the holiday season is here, nothing feels as heavenly as a mug of hot chocolate or a latte warming your hands as you sit in front of the fireplace in the living room.

During these cozy, lazy times, a lot of us don’t feel like waiting for five minutes for the milk to boil in a pan to make our hot beverage. But no matter how tempting it feels, there is one thing you should absolutely avoid doing: PUTTING MILK IN YOUR KEURIG WATER TANK.

If you want to know why putting milk in your Keurig is such a bad idea, read on. In this guide, we will share:

  • Why you should never ever put milk in a Keurig
  • What happens if you put milk in a Keurig
  • How you should clean out your Keurig if you put milk in it
  • What to do if you need to make hot milk straight from the coffee maker

But before that, you should know how a Keurig works.

How Does Keurig Work?

Keurig is the pioneer of single-serve coffee-pod coffee makers and now comes in several different models and features. But Keurig 1.0 or 2.0 models all basically have the same parts: a machine that contains a water tank and a single-serve coffee pod that contains enough coffee grounds to brew a single cup of coffee.

To make a cup of coffee, you need to fill your water tank with distilled water and place a K-Cup coffee pod into the built-in K-Cup holder. A sharp needle punctures the coffee pod when you close the cup holder. Depending on the model of the machine, you may see the message “Ready to Brew.”

You can press the appropriate button to start the brewing process. The machine then heats up the water inside the tank and pumps it through the coffee pod via the needle. The brewed coffee will then dribble into your cup within a minute.

Why You Should Never Ever Put Milk In A Keurig Water Tank

Keurig coffee makers are the most convenient ways to brew a single cup of coffee. Now that Keurig has come up with hot chocolate pods as well, it might seem like a bright idea to simply add milk instead of water in the reservoir. You are not alone in thinking this.

We are sure that a few precocious 8-year-olds, as well as some college students, have experimented with this idea just as we are sure that it ended with disastrous results.

As you can glean from the above sentences, putting milk in a Keurig is a really bad idea. The reason for that is that Keurig machines come equipped with a water tank — which is not a milk tank. This means that it should only be filled with water. Anything else will just clog the pipe system and the interior of the machine.

Additionally, Keurig machines are designed to heat up a single cup of water in seconds for rapid brewing. If you try to add milk to it, it can ruin not just your milk but your machine as well.

Some people have considered throwing out their almost brand-new machines because they made the mistake of putting in milk in their Keurig water tank.

What Happens If You Put Milk In Your Keurig

If you put milk in a Keurig, you will encounter at least one of these three issues:


Keurig is a very handy coffee maker since you can even leave water standing in its reservoir until you need to make coffee. However, we strongly recommend you do not use water that has been standing for twelve hours or more since bacteria can form in it. But leaving water in its reservoir for four or five hours isn’t a bad idea.

However, the same cannot be said for milk. Milk spoils rapidly at room temperature, and if you leave it in the warm confines of a Keurig water tank, it will not be long before it curdles.

mold in a coffee machine
The residue of milk will spoil and curdle which results to a sour smell that’s difficult to get rid of

So if you want to make hot chocolate or any milk-based beverage, you will need to add fresh, cold milk straight from your refrigerator to whatever heating tool you use, whether it is a microwave oven, a pan on the stovetop, or anything else. But remember, do not put milk in a Keurig water reservoir, whether it is for immediate or later use.

That’s because it is very difficult to wash out the milk from the container. Even if by some miracle, your milk doesn’t end up being burnt, its residue will spoil and curdle, leaving an impossibly sour smell that is very difficult to get rid of.


The heating coil in a Keurig is designed to quickly bring the water temperature to the boiling point in less than a minute. This rapid heating of water will burn your milk, giving you a sour or bitter-tasting beverage. Another thing that can indicate that your milk has burned is if you smell a strong, sharp odor after you heat up the milk in a Keurig.

This smell can be very strong and can permeate your entire kitchen and even the rest of your home.

Scorched Metal

The burned milk will form into curd and stick to the heating element of the Keurig. It may scorch the metal, and the buildup will prevent it from working efficiently.

Additionally, this hard milk crust is very difficult to remove since it may not be easy for you to access the internal parts of the machine. You can use a spoon or a scraper to clear the crust, but it can be quite tricky, and you may scratch and damage the components.

Can You Clean Your Keurig Machines After Adding Milk?

So does this mean that your Keurig machine is permanently out of commission and is only fit for the garbage can? Don’t lose hope yet. It may be possible to clean it, though it will require quite a bit of time and effort.

Follow the steps to clean your Keurig:

  • First of all, do not forget to turn off your Keurig machine as you don’t want any nasty shocks while cleaning your appliance.
  • Fetch your Keurig manual, and with the help of screwdrivers, dismantle your Keurig machine.
  • You can use a sponge scrubber to scrape off the crusty residue on the bottom. Be gentle with your ministrations, though, as you don’t want to damage the components. 
  • Boil some water in a kettle and add half a cup of vinegar to it. You can also add some baking soda to the solution if you want to make extra sure that your machine will be cleaned.
  • Place the solution in the Keurig water tank and let it sit for a while. If there is some milk crust left in your reservoir, hopefully, it will become loose because of the vinegar. You can use the scrubber to remove it.
  • Keurig machines don’t have a drain plug but do have an internal hose that you can take apart and allow the liquid inside to drain out and in the process, drain away from the milk buildup in the waterline. Once all the solids have been removed, you can now assemble your machine again and run several cleaning cycles.
  • Fill your water reservoir again with vinegar and baking powder solution, and then run a cycle without putting a K-cup pod in. One run may not be enough to clean out the sticky milk and the sour smell from the internal system, so you may have to repeat this process several times until the water runs clear, and the smell dissipates completely.
  • Rinse out your machine with a couple of cleansing cycles of just filtered water to get rid of the vinegar as well.

We hope that if you follow these steps, your Keurig machine will run well as new. If you are still experiencing issues with the machine, it is best to ask for advice at Keurig’s website or take it to a Keurig outlet.

What To Do If You Need To Make Hot Milk Straight Out Of The Coffee Maker?

What to do if you need to make hot milk straight out of the coffee maker?
Find milk pods that brew the same ways as K-cup coffee pods

If you want a coffee maker that accommodates milk, your single-serve Keurig coffee maker won’t cut it. There are two options for you:

If you are a Keurig fan, the K-Café coffee makers can heat up and froth your milk in a jiffy. It comes with a built-in milk heater and frother that can give you steamed, foamy milk in no time. In fact, it also gives you options to make espresso-based beverages like lattes and cappuccinos.

Besides that, other brands like Mr.Coffee Maker and Nespresso also come with milk tanks that can give you hot milk or milk-based beverages without you having to heat the milk separately.

Parting Shot

Your Keurig machine is a godsend if you want to make single-serve coffee with almost no wait time. But adding milk to the machine is not a great idea. Not only can it spoil your milk and make it undrinkable, but you may even have to say goodbye to your beloved machine.

If you must have automatic milk heating with your coffee, consider investing in K-Café machines that come with a milk container and frother.


  • AE Inman

    A E Inman is a direct response copywriter and humor blogger. When she's not poking fun at her attempts to start a writing business, she can be found in the tea aisle of her local import store, arguing with strangers over the merits of rare tea varietals. She enjoys writing copy while consuming copious amounts of coffee and gunpowder tea.