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Sunday, January 3, 2021

Sangiovese, the cultivar at Italy's core: Part I, the clones

Sangiovese is the most widely planted of the Italian varieties (63,000 ha; 10% of all plantings) and is the basis for some of the most important wines in Central Italy. I had previously written about the variety but ongoing research has yielded additional information, requiring an updating of the original material, as well as the way in which it is presented. Towards that end, I will present a more comprehensive view of the variety in four separate posts: clones, viticulture, winemaking, and wines. I begin herein with Part I, clones.

The Variety
The grape, the name of which translates to "Blood of Jove," is small-to-medium in size, round-to-oval in shape, and grows in tight clusters with wings at the shoulders. The skin is thin, with a deep-blue to dark-purple color. The flesh is translucent, seeded, and endowed with high acidity and medium-to-strong tannins.


In addition to the name Sangiovese, the variety has been referenced variously as: Sangiovese grosso, Sangiovese piccolo, Sangioveto, Sangiogheto, San Gioveto, San Zoveto, Prugnolo, Morellino, Brunello, and Nielluccio.

Research has shown it to be the offspring of Calabrese Contenuova and Ciliegiolo but this finding has been disputed by subsequent, competing research results.

A total of 70,948 ha of Sangiovese is planted worldwide, with 63,000 ha of that total located within the borders of Italy. Argentina (2804 ha), Romania (1700 ha), Corsica (1633 ha), California (1371 ha) and Australia (440 ha) are the other "significant" players on the field. Within Italy, plantings are concentrated within the Central provinces but are also to be found in Lombardia, Emilia Romagna, Valpolicella, Campania, and Sicily.

Clones
In their book Chianti Classico, Nesto and di Savino highlight some of the early confusion as regards Sangiovese biotypes. Writings from 1906 had identified two Sangiovese biotypes: Grosso (also called dolce) and Piccolo (also called forte). It was believed that the Grosso biotype had three distinct subgroups: Sangioveto in Chianti Classico, Prugnolo Gentile in Montepulciano, and Brunello (Sangiovese Grosso) in Montalcino. Post the 1990s, however, genetic studies have revealed all of the foregoing to be a single biotype differentiated by the growing environment. According to Professor Malle of the University of Florence (quoted in Nesto and di Savino), Sangiovese is "phenotypically unstable."

From 1960 to 1980, Sangiovese was grown almost exclusively for quantity. The most important goal in clonal research, according to Kerin O'Keefe (Brunello di Montalcino), is improving and stabilizing quality, with disease control as the main focus. Nesto and di Savino identify the characteristics that have the most value for biotype selection as:
  • Early ripening
  • Looser bunches -- less compact bunches allow air and light to pass through, provisding better resistance to many fungal diseases and giving berries in the middle of the bunch the chance to attain phenolic ripeness (O'Keefe)
  • Small bunches
  • Thick skins
  • Small berries
  • Growth that balances fruit and vegetation
  • Disease resistance.
Prior to the 1980s, clonal research on the Sangiovese variety was small scale and carried out primarily at the academic level. For example, Biondi Santi had aligned with the University of Florence and that collaboration at Il Greppo yielded the now-famous BBS11 clone which was itself selected over a number of clones grown at the facility over a five-harvest period (O'Keefe).

During the 1970s, four clones of Sangiovese were propagated for use. Nesto and di Savino refer to these as first-generation clones. They are shown in the table below. Of the four, T19 was never certified because of its virus load.

Table 1. First-Generation Sangiovese Clones (after Nesto and di Savino)

Clone

Organization

Characteristics

R10

Rauscedo

  • Original budwood selected from Lamole in Chianti Classico
  • Known as Grosso Lamole
  • High-yielding clone that was criticized in the 1990s for making pale, thin wines

R24

do.

  • Known as Media Predappio
  • Selected and developed in the Romagnon hills northeast of Tuscany
  • Popular for making fruity and moderately colored wines

F9

University of Florence

  • Selected from Tuscany
  • Deeper color than R10

T19

Viticulturist Remigio Bordessi in Emilio-Romagno

  • Deepest color, most sugar, highest acidity, lowest pH among all clones
  • Floral aromas and firm tannins a la R24
  • Matured later than all other Sangiovese clones
  • Loose bunches
  • Could not be certified because it had two viruses

In 1982, Banfi, in cooperation with the University of Milan, initiated a Sangiovese clonal study which initially identified 650 clones, further whittled down to 180 and then to 15 which represented "the greater part of the grape's inherent variables." From these 15 clones they distilled six (Janus 10, Janus 20, Tin 10, Tin 50, BF 30, BF 10) which were registered in 1996. The foregoing, plus the VCR5 and VCR6 clones selected from Il Poggione vineyards by Rauscedo, comprise Nesto and di Savino's second-generation clones.

Table 2. Banfi Clones (after Banfi)

Clone

Characteristics

BF 10

  • Medium-big clusters and berry, high yield and concentration of phenols and anthocyanins
  • Wine characterized by spicy and phenolic scents with high typicity and significant tannic content

BF 30

  • Medium clusters, medium-big berry, average yield, and high concentration of phenols and anthocyanins
  • The wine shows a high typicity with good structure and phenolic concentration
  • Aromas of red fruits, phenol, and tobacco
  • Good alcohol content

JANUS 10

  • Medium-small clusters and berries, average yield, higher-than-average sugar content
  • Good typicity with greater structure and phenolic content
  • Aroma of ripe apples and flowers

JANUS 20

  • Medium-small clusters and berries, lower-than-average yield
  • Wine of very high typicity, showing a deep color and good polyphenolic and alcohol content
  • Aromas of flowers and red fruits

TIN 10

  • Large cluster, medium berry, average yield, with high phenolic content
  • Aromas of ripe apple, flowers and spice
  • Good structure with high alcoholic strength and a higher-than-average polyphenolic level

TIN 50

  • Medium-large cluster and berries with high yield and polyphenolic content
  • Intense bouquet
  • Good typicity with high alcoholic structure and dry extract

As stipulated by Banfi, the goal of their research was not to identify a super clone but, rather, "a group of clones that together" could best harness the complexity and variability of Sangiovese. "As a result, starting in 1992 all of the new plantings of Sangiovese on the estate are characterized by the presence of at least three selected clones that are complementary to each other, chosen for the individual characteristics of the soils in each vineyard site" (Banfi).

The initiation of the Chianti Classico 2000 study signaled a changing approach to clonal research. This study was initially designed by the Chianti Classico Consorzio in 1987 with the goals of modernizing viticulture in the region and improving the quality of future wines (Tim Gaiser MS). The design of the effort included 16 experimental vineyards (planted over 25 ha) and five research cellars to vinify the grapes. This collaboration between the Chianti Classico Consorzio and the Universities of Florence and Pisa unfolded over 16 years and studied all aspects of cultivation to include cultivars, vine planting density, rootstocks, training systems, and soil management.

The initial portions of the study identified 239 clones in the Chianti Classico area and these were whittled down to 34 (24 Sangiovese, eight Canaiolo, and two Colorino) which had high immunity to common viral diseases. In 1995 these clones were planted to specific vineyard soils and resulted in the identification of eight new clones that were ideally suited to the Chianti Classico region. These clones were characterized by (Gaiser MS):
  • Smaller berries
  • Thicker skins
  • More open bunches
  • More consistency through varied climatic conditions
These eight new clones were registered as CCL 2000 nos. 1 - 8.

Another clone set that bears mentioning is the collaboration between Col d'Orcia and the University of Florence in the former's Poggio al Vento vineyard. The work yielded the SG-CDO-4 and SG-CDO-5 clones in 2003 and the SG-CDO-8 in 2001.

Massal Selection
Nesto and di Savino point to a movement among Sangiovese growers away from clonal selection and towards massal selection. Decanter describes mass(al) selection thusly:
... some growers prefer to plant new vineyards, or replace dead vines ... with wood taken from old vineyards planted before the days of clonal planting. By doing this, they can preserve the clonal variation of these older vineyards, many of which were planted with vines produced from wood taken from a region's successful vineyards. Thus their vineyards are populated with vines having significant clonal variation ...
For Nesto and di Savino, the Sangiovese growers are just plain comfortable with the performance of their selections that they propogate because they have observed their successful performance in the "target environment"over a long period.

I will continue this series with a future post on Sangiovese viticulture.


©Wine -- Mise en abyme

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