Italy is the paradise of mineral waters: besides holding the world record for consumption per person, our country has more than 300 springs, distributed over the mountain chains and in the plains. 
According to national and community regulations, mineral waters are classified primarily on the basis of fixed residue as lightly mineralised (mineral content, up to 50 mg/l), oligomineral (between 50 and 500 mg/l), mineral (up to 1.500 mg/l), and rich in mineral salts (>1.500 mg/l).

Fixed residue is one of the two key parameters used to measure the lightness of mineral water. It consists of the amount of inorganic substances contained in the water and is normally expressed in milligrams/litre. It is measured by having the water evaporate at 100 °C and by heating the residue at 180 °C.

The other parameter used to determine the lightness of mineral water is hardness, that is to say the quantity of calcium and magnesium salts contained in it. The salts of these two elements in solution may cause incrustations that appear hard and tightly-knit. Natural mineral water may be distinguished into very soft, soft, semi-hard, hard and very hard. However, hardness levels need not be stated on the label according to current regulations.
Each mineral water has unique properties, depending on types of salt dissolved in it.

Save for detailed requirements specified by a physician, we can all select water with a greater or lesser mineral salt content, with a greater or lesser degree of lightness, according to our own personal needs and preferences.

Thanks to Acqua Sant’Anna