The Water Dictionary

Plancoët

StillBreton

Plancoët is a natural mineral water from the Sassay spring in Plancoët, Côtes-d’Armor, Brittany. It is the only commercially bottled natural mineral water from Brittany and has held official NMW recognition since 1928. The source is accessed from a depth of approximately 110 m. The brand operates under Compagnie Fermière de Sassay.


Mineral composition

mg/L
Calcium24
Magnesium16
Sodium32
Sulfate50
Chloride38
Bicarbonate121
Hardness: 126 as CaCO₃Alkalinity: 99 as CaCO₃

Compositions can vary by season and source. Read our methodology.

Mineral character

Calcium is 24 mg/L, magnesium 16 mg/L, sodium 32 mg/L, sulphate 50 mg/L, chloride 38 mg/L, and bicarbonate 121 mg/L. Hardness is 126 mg/L as CaCO₃. The most distinctive feature is the pH of 4.6 — strongly acidic relative to almost all commercial mineral waters — combined with confirmed zero nitrate. Sulphate and chloride are relatively elevated for a still French water, reflecting the specific geological conditions at depth. Bicarbonate is the dominant anion but low in absolute terms for a water at this pH.


Use-case suitability


Used in these recipes


Where to buy

FR

Carrefour, Leclerc, Auchan, Intermarché

€0.40-0.60 per litre

Available across French supermarkets including Carrefour, Leclerc, Auchan, and Intermarché. Not widely available outside France. As of March 2026.