How to read these TDS numbers
TDS (Total Dissolved Solids) is the dry weight of everything dissolved in a litre of water — calcium, magnesium, sodium, potassium, bicarbonate, sulfate, chloride and trace minerals — usually reported as dry residue at 180 °C on European labels.
EU and FDA framework, simplified:
- Low mineral: below 250 mg/L (Evian, Acqua Panna, Volvic)
- Medium mineral: 250–500 mg/L (most premium still mineral waters)
- High mineral: 500–1,500 mg/L (San Pellegrino, Ferrarelle, Saratoga)
- Very high mineral: 1,500 mg/L+ (Gerolsteiner, Vichy Catalan, Borjomi, Mendocino)
