Did you know that an espresso is made up of 90% water and only 10% coffee?
In contrast, a filter coffee is composed of as much as 95% water.
Water thus has a dual role in coffee: solvent and main ingredient.
From this data, one can immediately see how choosing the right water to use is critical to the success of a good coffee.
Polluted or distilled, light or heavy, hard as ice or intangible as vapor?
And no, it is not, water is not odorless and tasteless!
Depending on the mineral salts, sodium, chlorine, and limestone dissolved in it or depending on purification methods, water changes a lot in taste and smell, and this is immediately reflected in the cup.
Chlorine itself, due to its oxidizing effect, is one of coffee’s worst enemies, as it makes it more bitter and makes our beloved espresso crema clearer.
The most suitable system for chlorine removal is definitely the installation of activated carbon filters.
In addition, we have often heard about water hardness, but exactly what does it mean?
Hardness is determined by the main mineral salts dissolved in it, namely magnesium and calcium. The more these two minerals are present, the harder the water will be.
They have a positive charge and are thus able to attract different aromatic compounds to themselves.
Some of these salts are therefore essential to be able to extract the flavors from ground coffee in the best possible way, but too strong an attraction will not allow the extraction of other substances, which are also essential for the success of a good espresso.
Therefore, we need to find the right hardness to extract the flavors of our mince to the maximum, but without affecting the other components.
Water used for espresso within the premises comes directly from the water supply. Therefore, to know its values, the quickest and easiest method is to read the bill or get a water analysis kit.
This control is essential to be able to offer your customers consistency in the taste of the product and the quality of the coffee offered.
While for bottled water, simply read the label. The values we need to be most careful about are: fixed residue and conductivity. In fact, it is these that indicate the amount of salts dissolved in a liter and thus tell us when a water is heavier and when it is lighter.
Now that we understand how to determine a harder and a lighter water, what is the ideal value for extracting good coffee?
The Specialty Coffee Association (SCA) has defined an ideal range of 50 to 175 mg/l, with hardness between 40 and 75 mg/l.
But beware! These data are valid for espresso, but not necessarily for all extraction methods.
For example, for a filter coffee, one should opt for water with a lower concentration of mineral salts.
This is because espresso has an average extraction time of 25 seconds. In that very short period of time we need to be able to extract as much flavor as possible, so we will need harder water.
In contrast, a filter coffee has much longer extraction times of several minutes and requires lighter water for this.
Now I want to reveal a little curiosity.
Every year there are decides of competitions in different areas of the coffee world, from tastings, to roasting competitions, to coffee competitions.
Participants in the last category not only select the coffee to bring to the competition and propose to the judges, but even choose the most suitable water to use and personally bring the bottles.
This hints at how high the bar for successful espresso can rise by paying attention to every single step performed and every component of the drink.