Raboso di Piave

Key characteristics of Raboso di Piave grapes

The Raboso di Piave variety is an ancient wine grape of Italian origin belonging to the Vitis vinifera species. The primary purpose of this grape is the production of dry red wines, as well as its use as a blending component to enhance the body, color, and acidity of other must batches. The Raboso di Piave grape variety is characterized by a very late ripening period. Harvesting traditionally takes place in the second half of October or the first ten days of November. The yield of the variety is abundant in favorable years, but production levels remain unstable across different seasons. Raboso di Piave is distinguished by tight, conical clusters of medium to large size, as well as berries with fleshy pulp, a thick durable skin, and a distinct simple flavor with high levels of free acids.

Morphological description of the Raboso di Piave grape variety

The following characteristic external features of the vegetative organs have been documented by ampelographers:

• Mature cane: The shoots are long, furrowed, and the vine is smooth to the touch. Moderate thickening is observed around the nodes. The surface has a reddish hue, and the internodes are characterized by medium to substantial length. The buds on the vine are large, prominent, and covered with tomentose pubescence.
• Young shoot: Spring growth is distinguished by a pale color; the shoots are practically white with a faint greenish tint. Tendrils form frequently and exhibit intense dark red pigmentation.
• Mature leaf: The blade varies in size, leaning toward large parameters. The leaves are thin but dense, rough to the touch, with a crinkled and wavy surface. The upper side of the leaf blade is completely hairless, while the lower side is covered with dense, pale green, felt-like pubescence. Three-lobed leaves predominate, while entire blades are less common. The lobes are characterized by medium sizes, and the sinuses between them are shallow but wide with open margins. The teeth are large, wide, and rounded with a sharp apex. The petiole is thick, of medium to substantial length. In late autumn, before leaf fall, the petioles and leaf blades of the Raboso di Piave grape variety acquire an intense red color.
• Cluster and berry: Clusters are winged, dense, and slightly conical in shape. The main axis of the cluster is thick, green, and reddish in certain variations. The berries are medium-sized and round, though due to heavy mutual compression within the tight clusters, the shape of the berries can become irregular. The skin is thick, tough, dark blue, and covered with a dense layer of grayish waxy bloom. The pulp is dense and fleshy, the juice is clear, and two to four seeds form in each berry.

Viticultural characteristics of the Raboso di Piave variety

The Raboso di Piave variety demonstrates high vegetative vigor on fertile soils, and the lifespan of own-rooted vines can reach one hundred years. The traditional vine training system involves long pruning of the canes, training the growth along high living supports made of maple or mulberry trees at a height of two to three meters above the ground, under which full bearing begins in the eighth or ninth year after planting. The cultivated method of growing on dry stakes with a fruiting cane pruned to a length of sixty centimeters to one meter, combined with a replacement spur, allows for the first harvest as early as the fourth or fifth year. The Raboso di Piave grape variety is distinguished by early budburst, making it regularly susceptible to spring frosts. The vine has a low capacity for lateral shoot formation, so the bushes practically do not restore their leaf apparatus through lateral growth after damage. The thick berry skin provides the variety with good resistance to powdery mildew (oidium). The main viticultural advantage of the berries is their complete resistance to shattering and gray rot, allowing clusters to remain on the vines during prolonged autumn dampness. However, the Raboso di Piave grape variety is highly susceptible to downy mildew (peronospora), which can completely defoliate the vines in epidemic years by the end of summer, stopping sugar accumulation at twelve percent compared to the normal fifteen to nineteen percent. Due to the instability of yields, plantings of this grape were historically replaced with more reliable American vines in several provinces of Treviso and Udine.

Winemaking and final product characteristics

Wine material made from pure Raboso di Piave grapes has a low must yield, as pressing one hectoliter of juice requires at least one hundred and eighty kilograms of dense pulp with a significant proportion of stems. The finished wine is characterized by a moderate strength of eight to eleven percent alcohol by volume, an extremely high titratable acidity ranging from twelve to twenty grams per liter, and a deep, intense color. In its youth, the wine has a rough, astringent, excessively tart taste, but it is valued on the market due to its intense varietal aroma of wild cherry (marasca). The Raboso di Piave variety is widely used as a wine for taglio (blending enhancer) during its first or second year of life to provide structure, tannins, and aroma to pale and weak wines of the lowland zones. Due to the massive content of acids and cream of tartar, the wine possesses a high aging potential and can develop in barrels and bottles for up to seven to eight years. A unique feature of aging wine from the Raboso di Piave variety is the complete loss of coloring pigments during extreme aging of more than ten years, resulting in the red wine completely bleaching to the state of a white wine. Significant differences are shown by the clones of the variety: the red-stemmed variation is less productive but contains more coloring matter and yields finer, more elegant wines compared to the basic green-stemmed Raboso di Piave grape.