While Dolly the Sheep and genetically engineered broccoli may smack of high technology and spark international controversy, clonal research has been an integral part of wine making's oldest and most vaulted traditions.
Defined as the "isolation and vegetative multiplication of individuals showing some valuable characters inside a variety," clonal selection has its origins in the earliest days of viticulture and is considered one of the tools that a vintner has at his disposal when planning a vineyard.
"When our teams started planting single vineyards of noble French varietals on the Castello Banfi estate in 1978," explained family proprietor Cristina Mariani, "our work was fairly straightforward." The University of Bordeaux and other institutions had already done much of the research on the genetic family of Cabernet Sauvignon, for example, and helped Banfi determine which clones were adapted for the soil types, altitude and sun exposure of the designated sites. But when it came to the region's traditional native variety, Sangiovese Brunello, the situation was quite different.
"The local vineyards of Sangiovese were a mix of 650 different individual clones," Ms. Mariani said. "They made field selections of the most productive, since quantity was their concern over quality, but that was based only on visual inspection of the grape bunches. If they did occasionally make a good wine, they didn't know why!"
Working together with the University of Milan, the Castello Banfi team found Sangiovese to be a much broader family than typical French varietals and with great variability within the population, running the spectrum from watery-light to inky-dark in terms of color alone. Just within Tuscany, Sangiovese is called "Sangioveto" in the Chianti zone, "Brunello" in the zone of Montalcino, "Prugnolo" around Montepulciano, "Calabrese" and "Nerino" near Arezzo, and "Morellino" along the western coast near Grosseto. "Our initial step," according to Ms. Mariani, "was to determine which of the differences were truly genetic and which were the result of mutations based on microclimate. Through extensive planting across the region starting in 1982, we subdivided the 650 clones into five fundamental types. From that basis we narrowed down 180 'presumed' clones, from which we isolated 15 which represent the greater part of the grape's inherent variables. Today we have definitive results for six of these clones, and research continues on the remaining nine."
Maurizio Marmugi, Chief Agronomist at Castello Banfi, described the work as a "weak selection" with the purpose of preserving Sangiovese's genetic inheritance of variability, but managing it for better winemaking results. "We are not looking for a super clone," he said. "Because Sangiovese, compared to other varietals, has such a high variability among its clones for sensitivity to weather conditions and other variables, it is what we call a 'population vine.' It produces the best and most consistent results when cultivated from vineyards that contain a limited variety of individual clones that thrive under different conditions, especially weather, which we have the least control over. Those clones must be complementary in their quality and production characteristics."
Banfi's work began with the planting of "catalogue fields," vineyards with two rows each of several clones. The individual rows were carefully monitored and individually harvested for separate microvinification in the Banfi winery, paying careful attention to the effects of the soil type they were planted in (defined by dug-out profiles), the position of the vineyard, and the weather conditions on each individual clone. Since vines take over three years to begin bearing fruit and Brunello is traditionally aged four years before release, the work is long term and painstaking. The result of this vineyard observation and continuous analytical tasting of the resulting wine is a ten-pointed chart that graphs the wine, which was vinified separately from each clone, according to the strengths of its principal characteristics (lightness, phenol, floral, astringency, structure, typicity, and the flavor sensations of red fruit, apple fruit, spice and tobacco). The theory is to overlay each of these charts, as on acetate sheets, to arrive at the nearly perfect decagon touching on all the key characteristics of Sangiovese Brunello.
The clonal selection continued in the winery, with comparative tastings of finished wines vinified from the isolated clones. Broad panels of expert tasters consistently indicated a preference for the wines made from a blend of several complementary clones over those made from only one or two clones.
Over the past three years, Banfi has been planting new Sangiovese vineyards on selected sites with the final selection of six clones in exact proportions determined to result in a consistently superior wine. They are named Janus 10, Janus 20, Tin 10, Tin 50, BF 30 and BF 10. The name Janus derives from the name of the Roman god representing beginnings and endings, while Tin was the Etruscan equivalent of the Roman's Bacchus, the god of wine. BF is simply an acronym for Banfi, where the clone was researched. The numbers next to the names indicate the rough percentage of each clone that should ideally be planted in a mixed-clone vineyard.
The Banfi clones were registered in 1996 and are among the 45 nationally approved clones for Sangiovese, and the only ones to be researched and submitted by an individual producer, as opposed to a nursery, region or university. "In part, Castello Banfi was in a good position to undertake a study of this extreme because of the breadth of our estate and our dedication to quality," observed Ms. Mariani. "But sharing the results with our fellow producers demonstrates our philosophy that by improving the overall quality of wines offered to the consumer by all producers, the whole wine world will benefit."
In addition to achieving a consistently superior expression of Brunello di Montalcino, the isolation of superior clones also improves the quality of the cuvées that include Sangiovese. A stronger Sangiovese allows for such blends to be made on the basis of the strength of Sangiovese as a complement to other varieties, as opposed to the need in the past to blend in order to overcome any weakness of Sangiovese. "Our work," said Ms. Mariani, "has brought Sangiovese to the level of Europe's noble varietals. This was, after all, was one of my family's fundamental goals in founding Castello Banfi in the first place."
CHARACTERISTICS OF THE BANFI CLONES
BF 10 - medium-big clusters and berry, high yield, high concentration of phenols and anthocyanins. The wine is characterized by spicy and phenolic scents, with a high typicity and a significant tannic content. Good for wines of medium aging or immediate consumption.
BF 30 - medium clusters, medium-big berry, average yield. The wine shows a high typicity, with good structure and phenolic concentration. Aroma of red fruits, phenol and tobacco, with good alcohol content.
JANUS 10 - medium-small clusters and berries, average yield, with a higher than average sugar content. Good typicity, with greater structure and phenolic content. The aroma of this wine is characterized by scents of ripe apple and flowers. Mixed with other clones, it helps emphasize the organoleptic characteristics of the final product.
JANUS 20 - medium-small cluster and berries, lower than average yield, a wine of very high typicity showing a deep color, good polyphenolic and alcohol content with a bouquet characterized by aromas of flowers and red fruits. When mixed with other clones in a proper percentage, it can give a higher aromatic complexity and guarantee high typicity.
TIN 10 - large cluster, medium berry, average yield, with high polyphenolic content. An aroma of ripe apple, flowers and spices, with ethereal hints characterizes the resulting wine; it has a good structure with high alcoholic strength and a polyphenolic level higher than average. Because of its unique characteristics, it is recommended to be mixed with other clones for the production of wines with medium to long aging potential.
TIN 50 - medium-large cluster and berries, with high yield and polyphenolic content. The resulting wine shows an intense bouquet; good typicity with high alcoholic structure and dry extract. A good base for producing high quality wines of long and medium aging.