Water knowledge

Spring water or mineral water? The difference is defined by law

Spring water sounds like untouched nature. Yet what may appear on a bottle is decided not by marketing but by food law: whether a water is sold as natural mineral water or as spring water depends on clearly defined requirements for origin, purity, bottling and mineralisation. Once you know the two categories, and how drinking water differs from them, you read every label with different eyes.

Updated August 2026 · 6 min read

Why is the designation of spring water regulated by law?

Bottled water is a foodstuff, and in Switzerland a simple principle applies to foodstuffs: anyone who buys a product should be able to rely on its designation. Food law therefore sets out precisely which requirements a water must meet before it may be sold as “natural mineral water” or as “spring water”. The terms are protected: a water may only bear these names if it demonstrably fulfils the relevant criteria.

For consumers, this is a genuine advantage. The category reveals at a glance where a water comes from, how it may be treated and how reliable its composition is. For mineral and spring water, the Swiss rules are also closely aligned with those of the EU; on both sides of the border, these two categories mean essentially the same thing.

Swiss law thus recognises two protected categories of bottled water: natural mineral water, with the strictest requirements, and spring water as a less strictly regulated intermediate level. Alongside them stands drinking water, with rules of its own. The following sections show what lies behind each category and how to tell them apart on the shelf.

What defines a natural mineral water?

Natural mineral water is the most strictly regulated category. Four characteristics are decisive. First, the water must come from an underground water deposit protected from contamination. Second, it must be of original purity: it may not be disinfected and may only be treated within narrow limits, for instance to remove iron or to add carbon dioxide. Third, it must be bottled directly at the source; transport in tanks is not permitted. And fourth, its mineralisation must be characteristic and constant: the content of minerals such as calcium, magnesium or sulphate may vary only within the range of natural fluctuation.

This constancy is more than a formality. It proves that a water has followed the same underground path over a long period, passing through the same layers of rock each time. The mineral analysis on the label is therefore the binding calling card of a spring. How widely waters can differ in their mineralisation is shown in our article on hard water. Compliance with the requirements is regularly monitored by the cantonal food safety authorities.

What is spring water – and where does the difference lie?

Spring water, too, comes from an underground water deposit and is bottled at the source. At first glance, the difference from mineral water therefore seems small. Legally, however, it is clear-cut: in its composition, spring water must meet the requirements that also apply to drinking water. Proof of original purity is not demanded in the same form. The central point: a constant, characteristic mineralisation is not a precondition.

The composition of a spring water may therefore fluctuate more. It may not be stated on the label at all, either: Swiss law prohibits any information on the composition of spring water and any presentation that invites confusion with natural mineral water. Spring water thus sits legally between drinking water and natural mineral water: a natural product of underground origin, but without the strict proofs of constancy and purity required of the top category. In practice this means that anyone who values a consistent, documented mineralisation will find that guarantee only in natural mineral water.

What applies to drinking water – and what exactly is table water?

Drinking water is the water from the tap. In Switzerland it is strictly monitored and, depending on the region, comes from groundwater, spring catchments or lake water. Unlike mineral and spring water, it may be treated, transported and blended from different origins; its legal benchmark is safety at the tap.

And table water? Swiss law does not recognise this category. The term comes from German food law, where it designates a manufactured product: water that may be blended from different types of water and have mineral salts or carbon dioxide added – with no link to a specific spring and no source designation. If you come across “table water” on the shelf, it is usually an imported bottle. Water bottled in Switzerland that has been blended or treated simply counts, in legal terms, as drinking water.

The category is not a mark of quality: all waters sold in Switzerland must be safe and beyond reproach. The designation informs you about origin, treatment and constancy; which water suits you remains a question of taste and mineralisation.

How do you recognise the category on the label?

A glance at the label is enough to classify a water with certainty. Look out for these features:

• “Natural mineral water”: the protected designation must appear written out in full on the label, together with the name of the spring and the place of bottling. It is accompanied by a table of the characteristic mineral values.
• “Spring water”: this designation is binding too. The location of the spring is stated, but information on the composition is not permitted on Swiss spring water labels. If a bottle carries no mineral table, that is a clear sign of spring water.
• “Table water”: a designation from German law that you may encounter on imported bottles. It stands for a manufactured product without protected spring origin and carries no source designation; added mineral salts or carbon dioxide appear in the declaration.
• Treatment notes: statements such as “carbonated”, “carbon dioxide removed” or “iron removed” show which of the few permitted processes have been applied.

Whether a water is still or sparkling says nothing about its category, by the way: every category exists with and without carbon dioxide. You can read more in our article on still water.

The Castels spring: constant mineralisation in practice

What the requirements for a natural mineral water look like in concrete terms can be seen at the Castels spring in Mels. Its infiltration area lies at over 2,000 m above sea level in the Sardona region, close to the UNESCO World Heritage Tectonic Arena Sardona. The water filters through layers of rock and stone for around 12 years before it is captured and bottled at the source. The result is a constant composition: 87 mg of calcium, 35 mg of magnesium, 265 mg of sulphate and 133 mg of hydrogen carbonate per litre, with just 4 mg of sodium and a total mineralisation of 540 mg – naturally alkaline with a pH of 8.0. This reliability is what separates a natural mineral water from a spring water. You will find more on the origin and the full analysis on the page our water.

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