How To Test Water Hardness for Espresso and Coffee Machines

by Whole Latte Love Updated: May 6, 2021 3 min read
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You have a new espresso or bean to cup coffee machine and it came with a water hardness test strip that looks like this. In this video I’ll tell you why it’s important, show you how to use it, and how to interpret the results.

So what the water hardness test strip measures is the level of minerals in the water you will be using in your machine. That’s important because harder water — which is water with a higher mineral content — will cause scale to build up faster within your machine. And long-term, scale build-up is the number one reason for premature machine failure.

If you’d like to see just what scale can do, check out our other videos that take a look inside espresso machine boilers with various amounts of scale build up.

Depending on your machine, you will use the results of the test to determine a descaling schedule. On many super-automatic bean to cup machines, the results of the test are entered into the machine and based on that use of the water filter, the machine will notify when it’s time to descale.

How to use the strip

So using the test strip is very easy. Remove it from its package by tearing at the line opposite the 4 squares. Now, just dip it in the water you will use in your machine for 1 second, remove from the water, and gently shake off any excess, then lay on a flat surface. After one minute, read the results.

Reading the results

Now reading the results is straightforward. Just count how many squares are red and how many are green. The color change can be a little subtle, but you should be able to see the difference between the red and green squares and count the number of each.

The packaging the strip came in has a key for interpreting the results but with words in German mixed in it can be a little confusing so here’s some help:

  • 4 green squares indicates total hardness of less than 3, which is extremely soft water
  • 1 red square equals a hardness of 4 to 7 which is very soft water
  • 2 red squares equals 7 to 14 which indicates soft water
  • 3 red squares is 14 to 21, indicating hard water
  • And if all 4 squares are red, total hardness is greater than 21, indicating very hard water.

What’s next?

With the test complete, depending on the machine, you will either enter the results into a menu system — which is typical for super-automatics — or use the information to determine descaling maintenance frequency with a semi-automatic.

How important is descaling?

It’s very important to keep up with descaling as recommended by the manufacturer. Now depending on your water hardness, you can extend the time between descaling maintenance by using an in tank or outboard water filter as recommended by the manufacturer. In some cases, a proper filter can even eliminate the need to descale completely.

If you need a filter or descaling products, we have them available for most every espresso and bean to cup machines.

Thanks for reading and if you’d like to get more of the good stuff on everything coffee be sure to come back later!.