- Coffee prep
Why water is so important.
Has this ever happened to you? The first morning of my vacation: I’m super proud that I brought my little coffee set with me, brew my favorite coffee with the stovetop pot, sit down in the sun with it – and yuck!
Kristin Oldenburg
Eew! Coffee that tastes like chlorine. Out of habit, I used tap water to make my coffee. Big mistake. In Spain, the US, France, Belgium, and several other countries, tap water is often chlorinated to disinfect it. I had forgotten about that…
What exactly is water quality?
When you consider that a cup of coffee consists of 98% water, it becomes clear that its quality is crucial for the perfect coffee taste. Water is the solvent for the more than 800 flavors contained in coffee. The minerals in the water are needed for their “extraction.” But please don’t reach for mineral water – balance is the most important aspect here.
Not too hard and not too soft.
The best coffee water has medium hardness and balanced mineralization. According to the SCA (Specialty Coffee Association), the optimal values are between 50 and 175 ppm. In this range, calcium and magnesium harmonize perfectly with the coffee aromas, resulting in a multifaceted, aromatic coffee.
If the water is too soft, the coffee will taste flat and acidic. If there are too many minerals (i.e., the water is too hard), it will taste bitter, the refined subtleties will be lost, and your tongue will feel dry or “furry.” And nobody wants that. Why is that? Depending on its mineral composition, the water reacts with the acids, sugars, and bitter compounds in the coffee and influences how evenly and completely these substances are dissolved. If it is too soft, the flavors are not transportable enough and the cup remains flat. If it is too hard, the bitter compounds become dominant.
Acidic or alkaline? The impact of the pH value.
Balance is also crucial when it comes to pH value. A value between 6.5 and 7.5 is ideal, with 7.0 being the best. This value ensures harmonious extraction. Fruitiness and sweetness are preserved, while bitter compounds are not emphasized. More acidic water emphasizes acids. If the water is more alkaline, the coffee becomes more bitter and loses its fruitiness.
The third factor: Water purity.
We have already discussed chlorine, but there are other types of water contamination: Heavy metals, pesticides, herbicides, microplastics – to name just a few. It is therefore advisable to use freshly filtered tap water, for example through activated carbon filters or water filters, or still, low-mineral spring water without any taste of its own.
The water should always be fresh and rich in oxygen: Stale or boiled water loses oxygen and makes the coffee taste bland. The best option is therefore water straight from the tap or from a freshly opened bottle.
Tip: Do not use mineral water. It is too highly mineralized and impairs extraction (see above).
My water, the unknown.
Because you can’t tell what the water is like just by looking at it, you should get test strips for water hardness (available from aquarium suppliers). If the water is very hard (rich in minerals) or chlorinated, it’s best to get a water filter for everyday use (you can also attach it directly to the faucet or the pipe).
And another tip: Please do not use distilled water, as this will not work for extraction – it needs minerals, but in the right balance.
Conclusion.
The best water for an optimal cup of coffee is fresh, neutrally mineralized, has medium hardness, and a pH value between 6.5 and 7.5. That’s the basis for a really good coffee. Not to mention the beans – 100% organic and fair trade, of course. But you already knew that.
