NUTSHELL
Mineral Water - The Essentials
If you only remember a few things about mineral water, make it these:
What you need to know
Not all water is the same
Two bottles labeled 'natural mineral water' can differ in mineral content by orders of magnitude. The difference is geological - it depends entirely on where the water flows underground.
The label is your starting point
Every mineral water bottle in the EU lists its main mineral composition. The key numbers are sodium, calcium, magnesium, bicarbonate, and fixed residue - but each source has a unique mineral profile and taste.
Fixed residue = total minerals
Fixed residue is a very useful number on the labels. Under 50 mg/L the water is very light. Above 1500 mg/L is highly mineralized. It also predicts taste - the higher it is, the stronger and more distinctive the taste.
Sodium varies the most
Sodium varies more than any other mineral - from less than 1 mg/L to over 1000 mg/L. Below 20 mg/L is considered low sodium. If you only check one number on the label, make it this one.
Calcium from water is absorbed similarly to calcium from milk
Waters above 100 mg/L of calcium can contribute meaningfully to daily intake - with bioavailability similar to dairy. Relevant if you avoid milk products.
Magnesium is often missing from diets
Magnesium deficiency is pretty common in Europe. Waters with a high magnesium content can help fill it. High magnesium also adds a slight bitter note to taste.
Bicarbonate makes water taste gentler
Under 50 mg/L the water feels sharp and leaves little aftertaste. Over 600 mg/L it feels smoother - it takes the edge off carbonation and reduces any harsh aftertaste.
How to choose
Decide what kind of water you want
Light and neutral, or with a stronger and more distinctive taste? Fixed residue tells you immediately - the higher, the stronger.
Think about what you want to avoid
High sodium if you watch your salt intake. High mineralization if you drink large amounts daily. High magnesium if you are sensitive to bitter notes.
Think about what you want to get from your water
Calcium if you eat little or no dairy. Magnesium if your diet is low in nuts and wholegrains. Bicarbonate if you find most waters too sharp or aggressive.
For a step-by-step guide, read How to choose the right water to drink.
Want to go deeper? Explore the full Learn section
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