What Is TDS in Water — and Why It Changes How Water Tastes

Every bottle of water has a number on it that most people skip right past: TDS. Total Dissolved Solids, measured in milligrams per liter. It sounds like chemistry-class trivia. It's actually the closest thing water has to a tasting note.

TDS is the sum of everything dissolved in the water — calcium, magnesium, sodium, potassium, bicarbonates, and trace minerals picked up on the water's journey through rock and soil. It doesn't tell you which minerals are there. But it tells you how much of them there are. And that changes everything about how the water tastes and feels.

Why TDS matters more than pH

pH gets all the marketing attention. But ask a water sommelier what shapes taste, and TDS comes first. We built our own lineup around it — here's our Mineralization Scale:

• Very low (0–50 mg/L). Minimal mineral content — soft, neutral, almost silky. Nothing competes with food or wine. This is where our Rainforest sits, at 20 mg/L — the quietest water we carry.
• Low (50–500 mg/L). A balanced mix of essential minerals, made for daily drinking. Enough structure to taste clean, not so much that it tires your palate.
• Medium (500–1,500 mg/L). True mineral waters — more beneficial minerals, more texture, a longer finish. This is where Three Bays sits at 1,300 mg/L: full-bodied and mineral.
• High (1,500+ mg/L). An abundance of minerals — distinctly mineral, sometimes challenging. A deliberate, acquired taste.

To put our own lineup on that scale: Rainforest at 20 mg/L and Three Bays at 1,300 mg/L are nearly opposite ends of the spectrum. Same category — "natural mineral water" — completely different experiences in the glass.

What TDS does in your mouth

Low-TDS water feels soft and disappears quickly. It hydrates without announcing itself, which is why chefs and sommeliers reach for it at the table — it doesn't argue with the food.

High-TDS water has presence. It coats the palate, finishes longer, and can taste faintly salty, sweet, or chalky depending on which minerals dominate. Some people drink it for the taste alone; others for the mineral content itself.

Neither is "better." They're different instruments. The mistake is treating all water as interchangeable and then wondering why one bottle feels flat and another feels electric.

How to use the number

Next time you're choosing a water, check the TDS before the pH:

• With dinner or wine: go low. You want the water to reset your palate, not compete.
• After a workout: go higher. Those dissolved minerals are electrolytes by another name.
• For all-day drinking: stay in the middle. Your palate won't fatigue.

And if a brand doesn't print its TDS at all? That's information too.

Explore the range: our lineup runs from Rainforest's whisper-light 20 mg/L to Three Bays' full-bodied 1,300 mg/L — taste what the number means. Shop the collection →