Crystals in a wine are neither noxious nor a sign of poor quality. These “diamonds” of the wine are only a hint for a high concentration of minerals in the wine. When these minerals join with the tartaric acid contained in the grapes, wine scale can develop in the course of time. Wine scale occurs most often, for instance, in selections, selection of berries, and selection of dried berries.
There the crystals on the lower side of the cork or on the wall of the bottle are a sign of long storage. Wine scale does not influence the quality or taste of a wine. However, as wine scale does not produce a pleasant mouth feeling, wine should be poured out carefully. Maybe one day you will have the occasion to have a look into an old, empty wine barrel: It will glisten like in an ice cave.