1. Loss of carbonic acid
When carbonic acid dissipates, the minerals in the mineral water lose their solubility and become visible. Once a bottle is opened, loss of carbonation is inevitable, but if you reseal the cap tightly you can slow down its loss and ensure the fresh taste of your Gerolsteiner. Storing the bottle in a cool place away from direct light also helps.
A drop in temperature, due to either weather conditions or incorrect storage, can change the balance of minerals and carbonic acid causing the minerals to fall out of suspension and become visible. The minerals can appear in a white, flaky or powdery residue in the bottle or as a crystalline coating on drinking glasses. Also, minor damage to bottles, caps and their threads can arise due to frost, which ultimately leads to carbonic acid escaping.
When mineral water is heated, the carbonic acid escapes. The effect of intense heat is that minerals combine and thus become visible. This does not impact the water quality and drinking heated mineral water is completely safe.
4. Open containers
Carbonic acid is also lost if mineral water is stored in open containers for a longer period. Valuable minerals can then precipitate as described above. This can cause mineral rings in drinking glasses or a light mineral film on the surface of the drink. Gerolsteiner therefore recommends pouring mineral water immediately into a drinking container before consumption and not letting it stand for a longer period of time, even if this is absolutely harmless.
What are the pH levels of Gerolsteiner waters?
Depending on the levels of mineralization and carbonic acid, most mineral waters tend to have a pH value in the neutral to slightly acidic range. Gerolsteiner’s pH value lies between 5.6 and 6.9. The still water “Naturell” is almost in a neutral range with a 6.9 pH and Gerolsteiner Sparkling has a 5.6 pH value.