When talking about high-quality coffee, the focus is often on factors such as the variety of the bean, the roasting method or the barista's skill. However, a fundamental element for good extraction that is often overlooked is water. Considering that coffee is 98% water, its quality has a direct and significant impact on the final flavour of the drink.
The ideal water for coffee extraction must have a precise balance of minerals. Water that is too soft, meaning low in minerals, may not be able to properly extract the aromatic compounds of the coffee, resulting in a flat, insipid cup. On the other hand, water that is too hard, rich in calcium and magnesium, can lead to over-extraction, with a bitter and unpleasant flavour.
For this reason, many industry professionals recommend using filtered or softened water. Filtering the water makes it possible to remove impurities such as chlorine, which can give the coffee an unpleasant taste, and to adjust the mineral level to achieve optimal extraction. As highlighted by Perfect Daily Grind, even small variations in water quality can have a significant impact on the flavour of the coffee.
Another problem linked to hard water is the build-up of limescale inside espresso machines. Limescale not only reduces the efficiency of the machine, but can also alter the water temperature during extraction, further compromising the quality of the coffee. Using filtered water or water treated with softening systems helps to prevent these problems and to extend the working life of the equipment.
There are also advanced solutions for controlling water quality, such as reverse osmosis systems, which remove practically all the minerals from the water, then allowing them to be reintroduced in precise proportions to obtain ideal water for coffee extraction. This type of system is particularly useful in coffee shops that want to maintain consistent coffee quality regardless of local variations in water quality.
In short, water quality is a fundamental element for making good coffee. Filtering the water and adjusting the mineral level not only improves extraction, but also protects the equipment and ensures that every cup of coffee brings out the best of the bean's characteristics. For anyone wishing to improve their coffee experience, investing in good water filtration is one of the first things to consider.
In our Brewing courses (here) you'll find all the answers.