The right coffee water - the coffee water instructions

Reading time: 4 minutes. This article is a short blog. You can find the detailed blog article here on our Swiss site.

Since your coffee drink consists of over 90% water and less than 2% dissolved coffee particles, it's worth taking a closer look at the water. Even if it tastes good as drinking water in a glass, there are a few criteria that make your drinking water a good start for your coffee drink.

What does good coffee water have to be like?

Basically, coffee water should be soft, usually softer than what comes out of the tap. There are two sizes:

• Total hardness = Magnesium Mg+2 and Calcium Ca2+
• Alkalinity = hydrogen carbonate = bicarbonate = HCO3-

For filter coffee the best values ​​are:

• Total hardness: 2 – 3 °dH
• Alkalinity: 1 – 2 °dH

For espresso the best values ​​are:

• Total hardness: 3 – 6 °dH
• Alkalinity: 2 – 4 °dH

Alkalinity is often referred to as carbonate hardness, which is not strictly speaking correct, but carbonate hardness has become established as a term.

That sounds very complicated. We'll explain to you here how you can achieve such good values, since it's very likely that you won't get such soft water from your tap.

How good is my water at home?

There are several ways to measure water hardness. A conductivity meter, a ppm meter and a droplet test (the simplest version). In the last case, 10ml of your water is put into a tube and a few drops of test liquid. You count the droplets and as soon as there is a color change, you know the hardness of the water. There is also the option of contacting the local water provider or visiting their website.

How and what does the table water filter filter?

Tabletop filter devices are inexpensive and widely used. Water is filled in and a maximum of 50% of the water is decarbonized. The other 50% simply runs through the device's activated carbon filter.

A short calculation example: From the tap we have drinking water with a total hardness of 16°dH and an alkalinity of 12°dH. After passing through the water filter, the alkalinity is halved to 6° dH, but the total hardness is only 10° dH. Since this is still far from perfect coffee water, we need a second run.

After the second run, the alkalinity is at 3°dH and the total hardness is at 7°dH. That's good, but we only get into the perfect range with the third filtering (1.5° dH alkalinity and 5.5° dH total hardness).

In some cases, 3 or more passes are necessary with table filter devices. Pretty complex!

The water filter with a fixed water connection

A luxury is a water filter with a permanent water connection, i.e. a permanently connected under-sink filter . It has a higher and more consistent filter performance and filters the water directly to the desired value. Decarbonization occurs through ion exchange, which in turn changes the PH value of the water.

But is this luxury necessary? If you have hard water and make a lot of coffee, it's worth purchasing. 90% of machine defects are caused by water that is too hard. If you consider the expensive purchase price of a good espresso machine, which you will certainly want to use for a long time, you should think about such a filter system. As a rule, it is cheaper to buy an under-sink filter than to have the portafilter machine serviced. In many cases, installation is simple, but can also be carried out by qualified personnel.

Another advantage is the reduced lime content in the water, which you will notice immediately in your kitchen, as white deposits will hardly be found.

Desalination plants are not an alternative!

In some houses, the drinking water system is connected to a desalination plant. This softens the water through ion exchange (calcium and magnesium are exchanged for sodium), but the alkalinity remains. When preparing coffee, this imbalance leads to the coffee tasting bland and boring because the interaction between balanced acids and bitter notes does not work. The only way out here is to go into the garden, as the water hoses are usually not connected to the desalination system.

Concrete procedure on the way to the right coffee water

We will be happy to help you achieve the right water hardness for you. This is how you do it.

1. You measure your existing water hardness with a droplet test or ask your water supplier.
2. You estimate the amount of water you need per day.
3. Send the total hardness and alkalinity (carbonate hardness) together with the amount of water and your type of coffee drink to support@kaffeemacher.de
4. We will get back to you as soon as possible with a specific recommendation on how you can achieve your target values.