The Standard
A clear, voluntary framework that defines what qualifies as mineralized water — and how well-mineralized it is — using the two minerals that matter most.
This framework is a working draft. The thresholds below are a proposal currently under review by our scientific advisory group. We are publishing them openly so the field can examine, test, and improve them. The first-star threshold in particular is expected to be lowered pending expert input.
What we measure
The standard is built on two essential minerals that are widely studied in drinking water and frequently removed during purification:
- Calcium (Ca) — contributes to taste and is one of the most common minerals in natural water.
- Magnesium (Mg) — often under-represented in modern diets and commonly stripped from purified water.
A rating reflects both the amount of these minerals and their balance. To earn a given star level, a water must meet the threshold for both calcium and magnesium.
How a rating is determined
- Mineral content is measured in milligrams per litre (mg/L).
- A water qualifies for the highest star level for which it meets both the calcium and magnesium minimums.
- Listing is voluntary: producers opt in and provide credible analysis of their water.
We define and promote the standard; we do not rank or criticize products that choose not to participate.
The five-star framework
To reach a level, a water must meet both the calcium and magnesium threshold for that level.
- Minimum MineralizedCalcium: ≥ 20 mg/LMagnesium: ≥ 10 mg/L
- EnhancedCalcium: ≥ 50 mg/LMagnesium: ≥ 25 mg/L
- FunctionalCalcium: ≥ 80 mg/LMagnesium: ≥ 40 mg/L
- Advanced BalancedCalcium: ≥ 150 mg/LMagnesium: ≥ 75 mg/L
- Premium ProfileCalcium: ≥ 200 mg/LMagnesium: ≥ 100 mg/L
Draft for review. Thresholds are provisional pending sign-off from the advisory group and may change. If you have data or expertise to contribute, please get in touch.
Built in the open, reviewed by experts.
The standard improves as more researchers, laboratories, and producers engage with it. Help us refine the thresholds, or apply to list a product that meets them.