Which WaterFor coffee?

Tap water, filtered water, or mineral water?

Gute Kaffeebohnen, die richtige Mühle, sorgfältige Zubereitung – und dann doch ein Espresso, der nicht ganz überzeugt. Was viele in diesem Moment nicht auf dem Schirm haben: Die Ursache liegt häufig nicht in der Bohne oder der Maschine, sondern im Wasser. Denn eine Tasse Kaffee besteht bis zu 90 % aus Wasser. Die Zusammensetzung des Wassers entscheidet darüber, welche Aromen aus dem Kaffeemehl gelöst werden, wie vollmundig der Espresso schmeckt und ob die Tasse bitter, flach oder rund ausfällt. Ob Leitungswasser, gefiltertes Wasser oder Mineralwasser für Kaffee die beste Wahl ist, erklären wir Dir jetzt!

Why does water matter when it comes to coffee?

Water is the solvent that extracts flavors, oils, and caffeine from the ground coffee during brewing. Which substances are extracted and in what quantities depends not only on temperature and extraction time, but also on the composition of the water itself.

The most important factor when it comes to coffee is water hardness—that is, the concentration of dissolved minerals in the water. These minerals act, in a sense, as bridges between the water and the coffee molecules: they help bind certain aromatic compounds and transfer them into the cup. If they’re missing, the flavor suffers. If they’re present in excess, unpleasant bitter notes quickly take over. The pH level of the water is also important: it should be neutral, meaning around 7.

Tap Water for Making Coffee

The quality of German tap water is strictly controlled to ensure it is safe to drink. Whether it is also suitable for making good coffee, however, is another matter. The problem is that water hardness varies considerably from region to region. For example, people living in Munich have significantly harder water than those in Hamburg or Berlin.

Water that is too hard

Hard water can negatively affect the taste of coffee: The high mineral concentration promotes the extraction of bitter compounds, making the coffee taste flat and chalky.

There's also a practical problem: hard water causes espresso machines to become calcified more quickly and shortens their lifespan if they aren't descaled regularly.

Tap water or filtered water for the Portafilter? We'll explain why water quality affects your espresso.

Water that is too soft

Water that is particularly soft has the opposite effect: Too few minerals cause the coffee's components to be extracted more intensely. The result is a very acidic coffee.

In addition, chlorine is often added to tap water for disinfection. Even in small amounts, it can introduce off-flavors and mask the delicate aromas of coffee.

Conclusion: Tap Water for Coffee?

Tap water may be suitable for coffee, but it isn't necessarily so. When brewing with a portafilter machine , a total hardness of about 3 to 7 °dH is recommended —that is, slightly soft to moderately hard water.

If you want to know how hard your water is, you can usually find the readings directly from your local water utility or on its website. It’s a simple first step that quickly provides clarity.

Filtered Water for Coffee: Is It Worth the Trouble?

Let's be honest: Who really feels like doing a chemistry experiment in the morning before the first espresso has even started brewing? A good water filter takes care of exactly that for you: It filters out limescale, chlorine, and unwanted aftertastes so that the full aroma of your coffee beans can shine through.

Activated carbon filters (e.g., from Brita): These classic countertop filters reliably remove chlorine from the water. Since they often only moderately reduce water hardness, it is recommended to run the water through the filter twice if the water is very hard.
Water Filters for Coffee Makers: The top of the line for caffeine junkies. They not only reduce limescale, but also adjust the water hardness to the optimal level and provide the perfect blend of minerals for coffee.

Our conclusion: Yes, it’s worth filtering tap water. Especially if you have hard tap water, a filter ensures consistently good taste and protects your machine from certain death by limescale.

Still bottled mineral water—an alternative?

If you want to skip the filtering but still enjoy really good coffee, the easiest option is to grab a bottle. Still mineral water can be a great alternative to plain tap water—as long as you pick the right one off the shelf. Above all, stay away from carbonated water. It would definitely not be good for your machine or the taste.

When purchasing water, it’s also worth taking a closer look at the mineral content table on the label. We recommend water with a total mineral content of 75 to 150 mg/l, moderate calcium and magnesium levels, and as low a sodium content as possible.

Our Conclusion: Which Water Do We Recommend?

If you care about using good coffee beans, you shouldn’t skimp on water in the wrong places. Our recommendation is therefore: Use filtered tap water or bottled water with optimal mineral content for your coffee.

If you’re lucky enough to live in a region with ideal water hardness, you can make excellent espresso even with tap water. Everyone else will notice a real difference with a good filter—not only in terms of taste, but also for the machine itself. Fewer limescale deposits mean less descaling, less wear and tear, and a longer lifespan for the machine. So investing in a good water filter pays off twice over.

Wasser, Bohnen, Maschine – Kaffeegenuss mit Espresso PerfettoGuter Espresso beginnt mit der richtigen Grundlage – und dazu gehört die Kaffee-Wasser-Qualität genauso wie die Bohne und die Maschine. Wer alle drei Faktoren im Blick hat, holt aus seinem Set-Up das Maximum heraus. Bei Espresso Perfetto haben wir alles parat, was Dein Barista-Herz begehrt. Von hochwertigen Siebträgermaschinen über die richtigen Espressobohnen bis hin zu den professionellen Filtersystemen und Zubehör. Schau in unserem Online-Shop vorbei oder besuch uns in einem unserer Stores – wir beraten Dich gerne persönlich, welches Setup am besten zu Dir passt.