“Unspecified indigenous grapes” does not refer to a single grape variety, but rather to a descriptive term used when a wine is made from a blend of several local varieties, the composition of which is not indicated on the label. This term reflects a winemaking tradition based on the preservation of old vines and the promotion of biodiversity, which is particularly significant in historically renowned wine-growing areas such as Sardinia and other parts of Italy where vineyards may harbour numerous local biotypes. Consequently, there is no uniform ampelographic profile: the bunch may vary in shape and compactness, as may the individual berries, whilst the leaf reflects the diversity of varieties present in the blend. The wine itself also takes on varying characteristics depending on the grapes used, the terroir and the winemaking techniques. In red wine expressions, it can offer an intense colour, aromas of ripe red fruits, Mediterranean scrub, myrtle, flowers and spices, with a full-bodied, vigorous and persistent palate; its structure and ageing potential can be enhanced by traditional fermentation and ageing in wood. The fascinating aspect of these wines lies precisely in their harmonious character: their identity does not rest on a single grape variety, but on the spontaneous balance of a local genetic heritage, often passed down through ancient vineyards and interpreted with a contemporary sensibility.