Mineral water is natural groundwater from underground springs that contains minerals and often carbonation. In Germany, it is strictly protected and must be bottled directly at the source. Behind the bar, it is indispensable: as a filler in long drinks, to dilute spirits, and as a thirst quencher for guests.
What defines mineral water
Mineral water comes from underground water reserves protected from contamination. Unlike tap water, it cannot be chemically treated—only iron, sulfur, and carbonation may be removed or added. The mineral content is naturally occurring and results from water seeping through rock layers. Each source has its own mineral composition, which is why waters taste different.
In Germany, the Mineral and Table Water Ordinance precisely regulates what can be called mineral water. It requires official recognition and must be bottled at the source. The mineral content varies widely: from under 50 milligrams per liter in low-mineral waters to over 1500 milligrams in highly mineralized varieties.
Carbonation levels in practice
For the bar, carbonation levels are more important than minerals. Three broad categories exist: still, medium, and classic. Still water has no or barely any carbonation, medium has a gentle effervescence, and classic is strongly sparkling. Some sources naturally contain carbonation, while most have it added technically.
Behind the bar, classic is most commonly used because it adds fizz to drinks and enhances aromas. For delicate spirits like aged rum or Whisky, still or medium water is preferred to avoid overpowering the flavor. Important: Once opened, bottles lose carbonation quickly, so they should always be tightly sealed and stored cold.
Use behind the bar
Mineral water is the most widely used filler. Gin & Tonic, Vodka Lemon, Aperol Spritz—none of these classics work without mineral water. It dilutes the spirit, makes it more drinkable, and adds volume to the glass. Always use cold water and pour it gently to preserve the carbonation.
Mineral water is also constantly requested neat, often served alongside wine or spirits. Many bartenders automatically offer it with an espresso or after a shot. In upscale bars, a water menu with different varieties may be available, though this is rare. In everyday settings, two or three good standard brands in various carbonation levels are sufficient.
Common misconceptions
Many believe mineral water is inherently healthier than tap water. This isn’t universally true—German tap water often has stricter limits and is tested more frequently. Mineral water stands out for consistent taste and natural mineral content, but both are nutritionally equivalent.
Another misconception: more carbonation means more minerals. The two are unrelated. Some low-mineral waters have strong fizz, while others don’t. For the bar, the key is that water tastes neutral and retains its carbonation. Cheap discount waters often lose their fizz quickly—something noticeable in the finished drink.
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Frequently asked questions
Can tap water be used instead of mineral water?
Technically yes, but tap water has no carbonation and tastes different depending on the region. For long drinks, fizz is essential, so tap water only works for still applications like Whisky with water.
How long does opened mineral water last?
Microbiologically several days when refrigerated, but carbonation escapes quickly. After one day, the effervescence is noticeably weaker. Behind the bar, opened bottles should be used the same evening or reserved for non-carbonation purposes.
Which carbonation level for which drink?
Classic for Highballs and spritzes, medium for gentle long drinks. Still water is used to dilute spirits neat or in Old Fashioneds, where only a few drops are needed. When in doubt: classic works almost everywhere.
Why do mineral waters taste different?
Each source has a unique mineral composition. High sodium content tastes slightly salty, sulfate can be bitter, and calcium and magnesium create a fuller flavor. For the bar, neutral varieties without dominant notes are best.
