The glass is the taster’s fundamental tool, just as the needle is for the tailor and the paintbrush is for the painter. Therefore, just as a tailor cannot work with a bent, broken needle and the painter cannot work with a stiff, dirty paintbrush, the taster, or the person who organizes a tasting, must see to it that the glasses that are to be used are perfectly clean, spotless, without residues and odorless.
One rule, which might initially seem to be little hygienic, yet is still valid every time one is washing glasses, is never to use detergents to clean them. This is because cleansing products contain odorous substances which, if not thoroughly removed through rinsing, can mingle with the delicate aromas of the water to be tasted, which would compromise the olfactory analysis.
When using a tasting glass for the first time, one must conduct a particularly thorough washing. This washing must be done first with warm water and then with vinegar, making sure that the latter perfectly bathes the entire surface of the glass walls. This careful operation is needed to perfectly remove greasy residues and dust which can accumulate on the glass. Following this, one should rinse the glass with generous amounts of hot water, making sure that the pungent odor of the vinegar is completely removed. A final rinse should be done with demineralized water so that the glass will dry when turned upside down without any risk of the formation of spots due to lime deposits and without the need to resort to drying the glass with a towel. In the event that this particular rinsing step is not done, it will be necessary to carefully dry the glass with a cloth that does not leave behind odors or any traces of fuzz. One example of a proper cloth is one that is made of linen, has been set aside exclusively for this purpose and has been washed using unscented soap.
During the drying process, the glass must be held with the hand cupped open. It is allowed to drip, and then quickly dried on the outside. Following this, still holding the glass firmly by its base, insert one corner of the cloth inside the glass with the thumb and move it down until it reaches the bottom. Then rotate the glass, holding the cloth firmly so that it dries both the inside and the outside of the glass at the same time.
Once an accurate cleaning has been done, the tasting glass is ready to be used. But it is better to proceed with a further check by holding the glass up against the light (in order to make sure that there are no deposits or spots) and by placing one’s nose over the mouth of the glass to check for the presence of odors. In the event that the glass is not in perfect condition, rinse and dry the glass once again. When this essential tasting tool has been perfectly cleaned, before proceeding with the organoleptic assessment, “prime” the glass with the water to be tasted. That is, place a small portion of water in the glass and have it run thoroughly along the sides of the glass and then remove it as thoroughly as possible, allowing it to drip out. At last, the glass is ready to be filled with the water to be tasted. After the tasting has been completed, clean the glass once again, excluding the phase of cleansing with vinegar. Rinsing the glasses with vinegar will be necessary at a later time in the event that the glasses have been stored in dusty, humid or unpleasant-smelling locations, if they have not been used recently, or if they have been left with traces of lipstick or fingerprints.
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.