Mineral Water Guide
Fixed Residue in Mineral Water
What It Is, Why It Matters, and How It Varies Between Waters
Fixed residue is one of the key parameters used to describe the mineral composition of water. It represents the total amount of minerals dissolved in the water.
The value is measured by evaporating one liter of water at 180°C and weighing the remaining mineral residue.
Because it reflects the overall mineral content, fixed residue is often used to classify mineral waters as light, moderately mineralized, or highly mineralized.
What Fixed Residue Represents
Fixed residue indicates the total concentration of dissolved minerals in water, including:
Waters with higher fixed residue generally contain larger quantities of dissolved minerals, while waters with low fixed residue have lighter mineral profiles.
How Fixed Residue Levels Vary in Mineral Water
The fixed residue of mineral water depends entirely on the geological formations through which the water travels underground.
Typical classifications include:
| Mineralization Level | Fixed Residue (mg/L) |
|---|---|
| Very low mineralization | < 50 mg/L |
| Low mineralization | 50-500 mg/L |
| Medium mineralization | 500-1,500 mg/L |
| High mineralization | > 1,500 mg/L |
These categories help describe the overall mineral intensity of a water.
Mineral Waters with Very Low Fixed Residue
Examples of mineral waters known for very low mineralization include:
| Water | Fixed Residue (mg/L) |
|---|---|
| Lauretana 🇮🇹 Italy | 14 |
| Sant'Anna 🇮🇹 Italy | 22 |
| Plose 🇮🇹 Italy | 22 |
These waters are typically described as light mineral waters, with a relatively low total mineral content.
Mineral Waters with High Fixed Residue
Examples of highly mineralized waters include:
| Water | Fixed Residue (mg/L) |
|---|---|
| Donat Mg 🇸🇮 Slovenia | 13,100 |
| Saint-Yorre 🇫🇷 France | 4,700 |
| Vichy Célestins 🇫🇷 France | 3,400 |
These waters contain very high levels of dissolved minerals, giving them a much stronger mineral profile.
Values based on official label data.
Fixed Residue and Individual Minerals
Fixed residue represents the sum of all dissolved minerals, but it does not indicate which specific minerals are present.
When People May Prefer Lower Mineralization
- When choosing lighter mineral waters
- When looking for a more neutral taste
- When preferring waters with lower overall mineral intake
When People May Prefer Higher Mineralization
- When selecting strongly mineralized waters
- When looking for waters rich in dissolved minerals
- When exploring waters traditionally associated with distinctive mineral profiles
Two waters with similar fixed residue values may still have very different compositions, depending on the balance of minerals such as calcium, magnesium, sodium, or bicarbonate.
Key Takeaway
Fixed residue reflects the total mineral content of water - and it can vary enormously, from just 14 mg/L to over 7,000 mg/L depending on the geological source.
Understanding this single number helps you quickly gauge how mineral-rich a water is and compare waters at a glance.
Explore Individual Minerals
Read also about the individual minerals that make up a water's total mineralization:
FAQ
What does fixed residue mean in water?
Fixed residue represents the total amount of dissolved minerals remaining after water is evaporated at 180°C.
Is fixed residue the same as mineralization?
Yes. Fixed residue is commonly used to describe the overall mineralization level of water.
What is considered low mineral water?
Waters with less than about 50 mg/L of fixed residue are considered very lightly mineralized.
Do highly mineralized waters taste different?
Yes. Waters with higher mineral content often have a stronger and more distinctive mineral taste.