Agriculture Reference
In-Depth Information
Different offi cially certifi ed clones are available:
R11 gives a high-acid wine, ISV V2 accumulates
higher levels of sugars; and more recent clones
such as VCR 19, 20, and 43 are characterized by
smaller, less compact bunches. For example,
the newer VCR clones are characterized by
musts that have acidity levels three times lower
than those from older clones, such as ISV-V2.
In general, Raboso Piave is very vigorous and
shows good adaptability to different soils. It has
a very long vegetative cycle, with early budbreak
and late ripening, which means it is highly sen-
sitive to bad weather (both spring frosts due to
its early fl owering and rainy autumns due its
late ripening).
Morphologically, Raboso Piave resembles
Raboso Veronese, but there are differences.
Veronese has much more jagged leaves than
Raboso Piave, and the grape bunch is also more
cylindrical and less compact; Piave's is shaped
like a truncated cone and is tightly packed. Viti-
culturally, Raboso Piave usually reaches opti-
mal ripeness about two weeks after Raboso
Veronese, and it prefers heavier clay soils than
does Veronese.
Resurgent interest in the Raboso Piave vari-
ety, fi nally recognized as a potentially high-
quality source of unique red wines, has led to
the formation of the Confraternity of Raboso
(www.confraternitarabosopiave.it), founded in
1996 in Vazzola di Piave with the commenda-
ble aim of promoting the knowledge, the aware-
ness, and the diffusion of the Raboso Piave
variety and its wines
.
wines are labeled
vendemmia tardiva
(late har-
vest), meaning that at least 60 percent of the
grapes used to make the wine were harvested on
or after the day of Santo Martino, November 11.
Late harvesting or air-drying the grapes has
always been a technique by which to reduce
raboso's acid ferocity. An interesting study on
gene expression relative to transcription prod-
ucts compared Raboso Piave grapes subjected
either to late harvest or to air-drying directly on
the vine, where grapes are left on the vine but
cut off from the rest of the plant by severing or
twisting the stalk feeding the grape bunch
(Bonghi, Cargnello, Ziliotto, Rizzini, Teo, Veil-
leux, et al. 2006). It was found that 80 percent
of the genes were differentially expressed in the
air-drying group compared to 10 percent in the
late-harvest group. The genes most affected in
the air-dried grapes were those responsible for
polyphenol synthesis (especially the reduction
of leucoanthocyanin reductase), for higher con-
centrations of acid phenols, and for lower levels
of polyphenols overall; the few genes affected
in the late-harvest group were essentially unre-
lated. The wines made from the air-dried
grapes were much smoother and softer, with
40 percent less total acidity than the control,
and 20 percent less than the late-harvest group.
The lower acidity levels were due to reductions
in both malic and tartaric acid. This biochemi-
cal result is due to the induction of transcrip-
tion by the genes that code for the enzymes
malate dehydrogenase and ATP-citrate lyase. In
practical terms, these results provide a scien-
tifi c basis for why air-dried Raboso wines tend
to taste more velvety and luscious than those
made from late-harvested grapes, which are
however characterized by greater freshness
and, in my view, refi nement.
Raboso Piave may be used alone or in blends
in a number of different DOCG (Piave Mala-
notte and Bagnoli Friularo), DOC (Bagnoli di
Sopra, Piave), and IGT wines (Alto Livenza,
Colli Trevigiani, delle Venezie, Marca Trevi-
giana, and more). Interestingly, relative to the
question of whether air-drying is the future of
Raboso
wines, the Piave Malanotte DOCG,
Which Wines to Choose and Why
Raboso Piave is found mainly in Veneto, in the
countryside around Treviso, and to a much
smaller extent, in Friuli Venezia Giulia. The
best wines are the DOC Piave Raboso: these
have to be aged a minimum of three years in
oak before release, and some estates, such as
Ornella Molon Traverso, age them longer still
(in their case, for two years more) in an effort to
smoothen the high total acidity. The DOC
Vicenza Raboso and the Friularo wines of the
area around Bagnoli can be good too. Some
