It is by far the most important aspect – and not only because it makes up 96 percent of coffee. Naturally, all modern baristas know the ideal type of water to get the very best from the coffee beans used.  More specifically, they know which minerals water must contain – as they are crucial for the taste of the coffee.

The magnesium contained in water, for example, gives coffee a balanced flavour. Calcium can help to neutralise the acidity in coffee a little and round off the taste. If baristas were to take a totally mineral-free water as a basis for their coffee, it would have an acidic taste as soft water increases the acidity of beans that have been roasted strongly and quickly. Water that is too hard is no better, however, as the alkaline effect of the water then neutralises all caffeic acids.

Obtaining the perfect coffee composition is a matter of finding a subtle balance, which can only be ensured by the right water.  Not too hard and not too soft. For many, a superb crema is vital for the coffee taste, especially in the case of espresso. If the water is too hard, the crema may not always be as good as desired.

Not every water-softening method leads to a better coffee as it normally eliminates limestone and minerals in an uncontrolled manner – and thus also essential flavouring agents and flavour carriers. Methods are needed that can be tailored to exactly the type of water desired.

It is an unwritten rule that a small glass of fresh, cool water should be served with coffee or espresso. Still, slightly mineralised water that goes well with the coffee water is best, so that it does not dominate the taste experience and distract the attention from the coffee itself. The glass of water makes the coffee even more digestible. It clears the palate and makes the coffee more genuine and pleasurable.