Why is water quality so important?
Water influences the extraction process—that is, how many and which ingredients are extracted from the coffee grounds. If the water is too hard, the coffee can taste flat or bitter. If it's too soft or filtered too aggressively, it will become thin and acidic. Water quality is therefore just as important as the quality of the coffee beans. While you can't improve poor-quality beans with high-quality water, you can ruin excellent coffee beans with poor-quality water.
What does the Specialty Coffee Association say?
The Specialty Coffee Association, SCA for short , has developed guidelines and standards for
Coffee water is dispensed. Specifically for the preparation of specialty coffee. The following requirements must be met.
- Clean, fresh water without odor (e.g. chlorine)
- Clear color
- Amount of dissolved particles should maximum 150 mg/l, in any case between 75 and 250 mg/l
- The alkalinity of the water should between 40 and 70 ppm (parts per million) CaCO3, calcium carbonate, are
- The water hardness must between 50 and 175 ppm CaCO3 (this corresponds to a hardness of 3 to a maximum of 10 °dH
- The pH value should be 7, but at least between 6 and 8
The minerals calcium, magnesium, and sodium are important for your water; they can positively influence the flavor of your coffee. However, too much iron or sodium is detrimental. Chlorine must be avoided at all costs, as this destroys the flavorings.
German toughness – what does that mean?
While we can drink tap water in the DACH region (and many other countries), it's still not the same as good water for coffee. In Germany alone, we have massive differences in hardness. The same applies within Austria and Switzerland. In Germany and Austria, water is classified using °dH, German hardness; in Switzerland, the French hardness, °fH, is also commonly used. Both hardness levels represent the calcium carbonate content, CaCO3, and thus the lime content in the water, expressed in degrees. Here's a formula (the only one in this article):
1 °dH = very soft water = 17.86 mg/l CaCO3 = 1.79 °fH
At 0 to 7 degrees German hardness you have soft water, from 8 to 14 it is medium hard water and from 14 to 21 degrees it is hard water.
Tap water: Can I use it?
Basically, yes – but with limitations. Water hardness varies greatly by region. In many cities, the water is too hard or even contains chlorine. The following tools can help you make tap water more suitable for coffee:
- Water filter (e.g. B. Brita): Reduces hardness and chlorine
- Previous analysis: Test strips or apps like Third Wave Water give you information about the composition
- Alternatives: For particularly sensitive coffees, bottled mineral water is recommended
Mineral water: A real alternative?
Yes, but not all of them! For coffee, you need water with a medium mineral content, low sodium, and no added carbonation. These brands often perform well:
- Volvic (soft, low residue)
- Lauretana
- Black Forest still
But you can also use many other types – it’s best to look at the ingredients of the water – especially the magnesium, calcium and sodium values.
Tip: Also pay attention to the TDS value (Total Dissolved Solids) – 75–150 mg/l is ideal.
It is best to mix water yourself
If you want to do it like the pros, you can mix your own coffee water. You can do this using distilled or demineralized water and mineral concentrates, for example. These are available from various manufacturers; we offer mineral concentrates from Apax Lab . This allows you to mix water to your liking and enhance/highlight various aspects of your desired coffee. The best part is, the drops work not only for coffee, but also for other beverages like tea, beer, juices, etc.
Lime and its effects
Tap water almost always contains limescale. As humans, we needn't be afraid – we don't develop limescale; in fact, a certain amount of limescale is good for us. Different rules apply to your coffee and your equipment. Too much limescale in the water makes your coffee chalky and tasteless. Hard water can also lead to limescale buildup in machines. This is particularly bad for fully automatic, portafilter, and other coffee machines. Very hard water – meaning water with a high mineral content – promotes corrosion inside machines. And demineralized water – meaning water with a low hardness – leads to limescale buildup.
Conclusion: The best water for your coffee
Since water makes up up to 98 percent of your coffee, it's advisable not to use just any water. While we can safely use tap water, we can also use much better water using simple means. The easiest method is to buy a suitable (still) mineral water or get a table water filter. If you want to go professional, mineral concentrates and distilled water will help you blend the perfect coffee water.
