How to Descale Your Keurig K-Classic Coffee Machine?

Keurig K-Classic is one of the most sought-after coffee machines available on the market nowadays. Proper maintenance of this machine is essential to keep the functionality at optimal levels. It also helps you increase the longevity of the device.

Descaling is a vital part of a proper maintenance schedule.

What is Descaling?

Water is the most dominant ingredient in a cup of coffee. But water isn’t just water. It contains minerals, such as magnesium and calcium. When you make coffee, these minerals get into the machine and form mineral buildup in and around the heating element of the coffee maker. These deposits are known as limescale (or ‘scale’ for short).

The process of eliminating the mineral deposits from the heating element is known as descaling!

How Often You Need to Descale Your Keurig Machine ?

The heating element of a coffee maker is not visible. So, mineral buildup often goes unnoticed for several months. You need to descale a coffee maker every 3 to 6 months to keep it in excellent working condition. The exact frequency can be decided based on the mineral content of the water you have been using and how many coffes you make

Most Keurig coffee machine manuals recommend that you descale your machine every three months or 300 coffees – whichever comes first.

That means if you use your machine often you may need to descale more frequently. Some examples of descaling frequencies are shown in the table below.

Number of coffees per dayRecommended descaling frequency
1-2Every 3 months
3-4Every 3 months
5-8Every 2 months
8-10Every month
examples of descaling frequencies based on use

The frequency of descaling also largely depends on what is known as your ‘water hardness’ – which essentially means how much mineral salts are present in your town or city’s water supply. Areas with high water hardness will require you to descale your machine more often, and areas with low water hardness can reduce the amount of maintenance required.

Some models of Keurig machines including the K-Classic have a warning light that will turn orange to alert you that the machine needs to be descaled. 

How long will it take?

The entire process to descale your K-Classic Machine should take between 20 and 30 minutes.

What you will need.

To descale your Keurig machine, you’ll need a descaling solution kit. A bottle of descaler that works for all machines costs about $15 from the Keurig website. Alternatively, we’ve created our own ecological product which you can check out here.

What you’ll need:

  • Descaling Solution – This is an eco descaler from amazon which is excellent value for money.
  • Clean water
  • A cleaning capsule, or one of our Green Pods (empty), to clean the brewing unit.

Check whether there is any beverage pod in the K-Cup pod holder. You should remove it before descaling. You should also remove the water filter too or replace it with a new one at the end of the descaling process.

A step-by-step guide on how to descale a Keurig K Classic coffee machine

The entire process can be divided into 3 steps.

  • Exterior clean
  • Descaling Solution Rinse
  • Descaling Rinse & Repeat
  • Fresh Water Rinse

Step 1: Exterior clean

Use a wet cloth with a small amount of detergent to wipe down the body of the machine. It’s important not to wash the machine in the sink, as water can get inside and damage the electronics as well as causing rust.

Step 2: Descaling Solution Rinse

Nest we need to mix up the descaling solution and run it through the machine.

  1. Turn the power off by pressing the power button
  2. Fill the water reservoir with a mix of desclaing solution and water. If you’re using the Keurig descaler, use one bottle of descaler, and then refil with one bottle of water to achieve a 1:1 ratio. If you’re using another descaler, then follow the instructions on the back.
  3. Turn the power on by pressing the power button
  4. Insert a container or mug under the drip tray.
  5. Lift and lower the handle and choose the largest brew size to run a rinse.

Step 3: Leave to stand once descaled

  1. Repeat the rinsing brew process and stop when the Add Water light turns on. You should not use a K-Cup pod during this process.
  2. Keep the Keurig K Classic coffee machine on and allow the brewer to stand for anywhere from ten minutes to half an hour.
  3. Remove the residual solution from the reservoir rinse. Fill with fresh cold water.

Step 4: Fresh Water Rinse

  1. The next step is to pour fresh water into the water reservoir until the water level reaches the MAX FILL line.
  2. Then, put the large ceramic mug on the drip tray plate
  3. With the largest brew size, you must run a rinsing brew. Don’t use K-Cup Pod while running the rinsing brew.
  4. Empty the contents available on the mug into the sink
  5. With the largest brew size, keep brewing to complete at least 12 rinsing brews.
  6. During the entire process, you may have to refill the reservoir at least once


These are three steps you need to follow to descale your Keurig K Classic machine. There’s also this video below from the Keurig youtube channel to help visualize the process!

Frequently asked questions and issues?

Here are some of the issues you may experience while performing the descaling task:

  • Foam dispensation
  • Brewer not filling properly
  • can you use vinegar instead of descaling soltion
  • What is descaling solution made from?
  • Can you make your own descaling soltuion?
  • Can i use any descaler in my K-Classic machine?
  • What happens if i dont descale my coffee machine?
  • Is decaling soltion toxic
  • Can you descale with baking soda?

Why is there foam coming out from the coffee machine?

When you perform this task, you may find foam coming out from the brewer due to the cleaning action of the descaling solution. Don’t panic. It is the aftereffect of the reaction between the descaling solution and mineral deposit.

It just means your machine is well overdue a clean!

Keurig not filling correctly?

When you descale a Keurig K Classic machine with a higher calcium scale quantity, you may find the brewer not filling accurately after adding the descaling agent. This situation leads to ineffective scale removal. You may also hear the sound of air blowing out.

To address this issue, you must switch off and unplug the brewer. Then, you have to remove the descaling solution from the reservoir and clean it thoroughly. Water must be refilled before plugging and turning the power on. The next step is to repeat the Fresh Water Rinse cycle recommended in Step 3.

Under normal circumstances, the issue will be resolved. If you experience the same problem again, you must keep the brewer unplugged for half an hour before starting the rinsing task.

Can you use vinegar instead of descaling solution?

Scientifically speaking, cleaning your Keurig machine with vinegar is almost exactly the same as with a commercial descaler solution.

Unfortunately, however, vinegar tends to peel off the scale build up in flakes which could clog your machine causing irreparable damage. We’ve heard numerous cases of people having to throw out their coffee machine because of this. We’d recommend sticking with a commercial descaling product.

What is a descaling solution made of?

Descaling solution is generally an acidic chemical that is capable of dissolving mineral salts such as oxides and carbonates. Notable descaling agents include acetic acid, citric acid, and lactic acid. These are all food-safe chemicals, however citric and acetic acid do impart a more noticeable taste to the machine, thus lactic acid is typically preferred.

Can you make your own descaling solution?

You can make your own descaling solution using vinegar or citric acid, though we’d recommend using a commercial descaling product in a concentration that is proven not to damage your machine.

Can I use any descaler in my K-Classic Machine?

Yes, in fact, you can use all descaling products in any brand of coffee machine.

What happens if you don’t descale your coffee machine?

Scale builds up inside the pipes restricting the flow of water. If this happens inside the heating element it prevents water from reaching its optimal brewing temperature. When this happens it’s impossible to extract the full flavor from the coffee pods and the flavor will become weak. Severe scale buildup can clog water flow completely, causing a machine to stop working

Is descaling solution toxic?

Our favorite Delonghi Eco-decaulk descaling solution is completely non-tox and eco-friendly. It’s made from lactic acid which is food safe in moderate doses. Other descaling solutions may use caustic chemicals such as sodium hydroxide which is highly toxic, so please check the label if unsure.

Can you descale with baking soda?

We don’t recommend using baking soda to descale your coffee machine.

One thought on “How to Descale Your Keurig K-Classic Coffee Machine?

  1. Pingback: Is Keurig Safe? The Dangers of Keurig K-cups – The Green Pods

Leave a Reply

Your email address will not be published. Required fields are marked *