If the need arises to chill water rapidly, place the bottle in a chiller or in the freezer for a few minutes. However, never serve ice in a glass of water.
Adding ice strongly alters the flavor of the water, creating a mixture of two waters with completely different natures.
Also avoid adding lemon juice or lemon slices, although many believe this to be offering water that better quenches the thirst. Water is the most thirst-quenching product that nature has to offer, and the addition of other substances changes its intrinsic characteristics and properties.
Finally, avoid adding still water to sparkling water or vice versa, as you would likely end up ruining two prodigies of nature in one feel swoop.
This text is taken from The S.Pellegrino and Acqua Panna Water Codex, a book written by international sommelier Giuseppe Vaccarini and Claudia Moriondo (Doctorate in Food Preparation Science). With this book S.Pellegrino & Acqua Panna studied and codified the guidelines, the best techniques and tools to conduct water tasting, with the aim to create a common language for everyone who whish to explore this topic.