Why does my Keurig say not to use distilled water?

If you’re reading this article, you’re probably wondering what kind of water should be used in your Keurig. Many people want their new Keurig to last as long as possible. If you’ve purchased your Keurig more recently, you probably read a statement in the Use & Care Guide, “Do not use distilled water.” So why does Keurig say not to use distilled water my coffee maker?

Understanding Distilled Water

What is distilled water? How would distilled water be different from tap or spring water? These questions must first be answered before we can understand how it will affect the Keurig coffee maker and the coffee it produces.

How Distilled Water is Made

Distilled water is basically the steam from boiled water converted back to liquid. So if you want to make distilled water, all you have to do is boil water, capture the steam, cool it, and it will give you distilled water.

When the water is boiled and the steam converted back into a liquid, it purifies the water. So if you test the water before and after it is distilled, you will find that there is nothing (or barely anything) in the distilled water compared to before it was distilled.

There are other methods used to purify water, like reverse osmosis, but I will mainly use distilled water as my term referring to water with the minerals removed.

What Distilled Water Is Made Of

So basically distilled water doesn’t have anything in it except for hydrogen and oxygen (H2O). Other forms of water, like tap or spring water, have minerals mixed in with the hydrogen and oxygen.

One thing to keep in mind is water acts as a vacuum when it is distilled. It absorbs its surroundings more than tap or spring water. This factors into things as we answer the question, “Why does Keurig say not to use distilled water my coffee maker?” It also applies to how the water interacts with the Keurig machine along with how the coffee comes out when brewed.

Sensors in the Keurig Machine

So there are different people who state different reasons why Keurig says not to use distilled water. The first reason has to do with the sensors.

Newer Keurig 2.0 models have sensors in the machines that detect how much water is in the coffee maker. Think about the light on the machine that says “Add water.” How does it know when you should add water? It’s through the sensors.

Regarding the sensors, it does not only apply to the “Add Water” sensor. It can apply to other sensors within the Keurig coffee maker. That is important to keep in mind.

Electricity and Water

Most of the time, when we think about electricity and water, we think of water conducting electricity. An article by the US Geological Survey states explains that pure water (distilled water) actually insulates the water. It’s the minerals (or ions) in the water that cause it to conduct electricity.

This is interesting, because the normal thought is that water conducts electricity. According to this article, it’s actually the minerals within the water that are causing the water to conduct the electricity. That changes the common view on how water acts within a Keurig.

Sensor Functionality

So let’s think about that regarding the Keurig coffee maker sensors. The lack of minerals in the water may not cause the sensors to conduct the electrical impulses to detect the water. What does that lead to?

The lack of electrical conductivity leads to the sensors not detecting water in parts of the Keurig. This could lead to a machine error. It could also lead to false readings. That could lead to the machine malfunctioning. So without minerals in the water, the sensors may not function correctly.

Mineral Buildup in the Coffee Maker

Another reason the question, “Why does Keurig say not to use distilled water my coffee maker?” comes up is related to mineral buildup in the machine. When you use water that has a lot of minerals, it can lead to mineral buildup. Using distilled water won’t lead to mineral buildup since there are no minerals in the water.

Preventing Mineral Buildup

So does Keurig want me to have mineral buildup in my Keurig coffee maker? Keurig includes descaling instructions in their user guide, which indicates they know minerals and scales will build up in their coffee machines. Keurig recognizes that water with minerals leads to mineral buildup.

Many people will see using distilled or reverse osmosis water as a way to avoid the mineral buildup. This will lead to people saving time and money. They won’t have to spend money nor time on a descaling solution. At the very least, they won’t need to do it as often.

The Opposite Effect

It may seem like a benefit to have less mineral buildup, but there is another factor to consider. Since distilled water acts like a vacuum and absorbs its surroundings, the plastics and other metal parts of the Keurig machine could get absorbed into the water. It may not sound good, but it’s a reality to consider.

Avoiding mineral buildup and avoiding the need to descale the machine may seem like a benefit, but what if damage occurred to the machine from the opposite standpoint? There is the possibility that using distilled water in the machine could cause parts to wear out prematurely due to the extra absorbtion from the distilled water.

As distilled water is used on a regular basis in the machine, it could lead to parts breaking down due to the water absorbing its surroundings. This is another reason Keurig may say not to use distilled water.

The Coffee Taste

I was at the store recently and was looking at a bag of coffee beans. Interestingly, the back of the bag had brewing suggestions. It specifically said, “Never use distilled or soft water.” That got me thinking and researching this more, as Keurig is not the only one saying not to use distilled water. So I’d like to move on to discussing how distilled water affects the taste of coffee.

Taste Preferences

Some people say that coffee tastes much better when using distilled water. Others say that the coffee doesn’t taste as good with distilled water. It’s a debate that is ongoing.

There is a report of someone contacting Keurig on a Reddit forum about this. Keurig told them that it gives the coffee a “flat” taste. So it seems Keurig takes the side of the debate that coffee doesn’t taste as good when using distilled water.

Acidity and Alkalinity

An article by the Specialty Coffee Association discusses how different minerals, particles, and substances in the water can affect the taste of coffee. In addition, minerals in the water affect whether the water is more acidic or alkaline. These factors affect the taste of the coffee. This is another factor to consider regarding how distilled water affects the taste of coffee.

There is certainly a debate involved when looking at whether distilled water leads to a better or a worse taste. You will need to make that determination for yourself as to whether you like it better or not.

Health and Safety Reasons

The last, but not least, reason I can see Keurig saying not to use distilled water is for health and safety reasons. Again, there is debate on this subject, but many people say drinking distilled water is not safe and can have negative health consequences.

Safety of Drinking Distilled Water

Since coffee is primarily made up of water, the water needs to be safe. This post will not cover the specifics of the safety of distilled water, but there is an article on the World Health Organization’s website that gets into details about health risks from drinking water without minerals.

As this article is looking at why Keurig says not to use distilled water in the coffee maker, this potential safety concern could be a reason for why they say this.

Plastic and Metal Absorption

More specifically, we discussed how distilled water acts like a vacuum in that it absorbs its surroundings.

There is a higher chance of plastics and metals from the Keurig getting absorbed into the water when using distilled water. This has the potential to have negative health consequences.

In that sense, not only could there be a general safety concern for consuming distilled water, but there could be a specific safety concern if the plastics and metals in the Keurig coffee maker are absorbed into the distilled water. This could be another reason why Keurig says not to use distilled water in their coffee maker.

Final Thoughts

So asking, “Why does Keurig say not to use distilled water my coffee maker?” has many potential and legitimate answers. It is not 100% clear, as Keurig doesn’t officially say their reasons.

There seem to be three main answers. The first is that there could be problems with the machine’s functionality. The second is that it may negatively affect the taste of the brewed coffee. The third is there could be potential safety and health risks.

I hope this article was helpful. If you have any questions or comments, feel free to contact us. Have a great day!

As a disclaimer: This post is not directly making any specific recommendations for you personally. The authors of this post do not directly represent Keurig and are not medical experts. Hot Coffee Brewing and its authors are not responsible for any damage to your Keurig machine. For any health-related questions, please consult and discuss them with your doctor. This post is not medical advice.