Comparison & choice

Best mineral water: what really tells you about quality

There is no such thing as the best mineral water. There is the water that suits your purpose and your palate – and there are the analysis values on the label that make every brand comparable. Once you can read them, you no longer need a ranking.

Updated August 2026 · 5 min read

Hardly any other foodstuff discloses its composition as openly as natural mineral water. Every bottle carries the complete analysis on its label, tested and legible for everyone. That is exactly where the comparison takes place that rankings can only claim to deliver.

Why the best mineral water cannot exist

Tests and best-of lists work with fixed criteria such as sensory profile, mineral content, packaging or price. That is a legitimate approach. But every scheme weights things differently, and none weights them the way you would. If the magnesium value matters to you, a top mark for taste is of little use. If you are looking for a still water to go with meals, the winner of a sparkling-water tasting will not get you anywhere.

Then there is the palate. Whether a water comes across as soft or distinctive depends on its mineralisation, and what one person perceives as balanced tastes flat to another. So the question is not which water is objectively the best, but which one suits your purpose and your taste. Both are on the label.

Reading the label like a professional

Natural mineral water is among the most strictly regulated foodstuffs in Switzerland. It must come from a protected underground source, be pure at origin and declare its characteristic values. Five figures are enough to place any label.

• Total mineralisation: the sum of all dissolved minerals. The usual classification: lightly mineralised below 500 mg/l, medium between 500 and 1,500 mg/l, high above 1,500 mg/l. Light waters taste neutral, highly mineralised ones noticeably stronger.
• Calcium and magnesium: the two minerals people ask about most often. Both perform central tasks in the body, for bones, muscles and nerves among other things. Their content varies between springs by more than a factor of ten.
• Sodium: decisive for anyone watching their salt intake. The range runs from a few milligrams to several hundred per litre. The statement ‘suitable for a low-sodium diet’ is regulated by law and appears only on labels that meet the requirement.
• Sulphate and hydrogen carbonate: the quiet flavour-shapers. Sulphate brings a slightly dry, mineral note, while hydrogen carbonate has a balancing effect and rounds a water off.
• pH value: below 7 a water is acidic, above 7 alkaline. Still waters usually sit between 6 and 8; carbonation lowers the value noticeably.

Working through a label: the reading example

How these figures read in practice is best shown on a concrete label. As a reading example, and expressly not as a recommendation: the analysis of the Castels spring in Mels, from which Piz Sardona is bottled.

The reading: 540 mg/l sits just inside the medium range. The water has noticeable character, then, yet remains a long way from heavy, salty-tasting waters. Calcium and magnesium stand in a ratio of roughly 2.5 to 1, both in appreciable amounts. Four milligrams of sodium per litre is remarkably little; the water therefore also fits a deliberately low-salt diet. The sulphate value of 265 mg/l provides a dry, mineral note, and the pH of 8.0 marks the water out as naturally alkaline. The same exercise works with any label on the shelf, in about a minute.

Four purposes, four requirements

More productive than the search for the best water is the question of what it is for.

• Sport and heavy sweating: with sweat, the body loses minerals, above all sodium and magnesium. Waters with a higher mineralisation replenish the stores faster than light ones.
• A low-sodium diet: what counts here is a low sodium value, and it is there in black and white in the analysis. A quick glance is enough.
• Coffee and tea: soft, lightly mineralised water lets aromas come through more clearly; a high carbonate hardness masks fine roasting notes and scales up the machine into the bargain.
• With meals and with wine: a still water with moderate mineralisation accompanies without pushing itself forward. Plenty of carbonation or very high mineral values can mask delicate aromas.

Strict legal limits apply to mineral water that is suitable for preparing infant formula. Look for the corresponding statement on the label; only waters that demonstrably meet the requirements may carry it.

Consistency and origin: the underrated criteria

One criterion appears in hardly any comparison, even though it defines the core of the category: consistency. Natural mineral water must remain stable in its composition, year after year, within the range of natural variation. If you know a brand, you also know its profile, today as in five years’ time. How mineral water differs from other types of water is explained in the article Spring water or mineral water.

Origin, too, is a sober criterion, not a marketing theme. Short transport routes save emissions, and if you know a spring’s catchment area, you know which rock your water has flowed through. Switzerland is geographically fortunate here: plenty of mountains and short distances. The article Swiss mineral water gives an overview of the local variety.

And Piz Sardona? You now know its figures. The water travels for around twelve years through the rock of the UNESCO World Heritage Tectonic Arena Sardona before it surfaces in Mels; the result is set out above in the reading example. Whether it suits your purpose is something the label will tell you faster than any ranking.

Frequently asked questions