Sunday, February 10, 2013

Part III -- Macro-Level characteristics: The definitive comparison of Champagne, Franciacorta, Prosecco, and Cava

What I refer to as macro-level characteristics are critical determinants of wine quality and in this post I detail the relative positions of each of the subject wines vis a vis these elements.

Location

The first major characteristic examined is location. Champagne is located at 49ºN latitude, 160 kilometers to the east of Paris, while Franciacorta (represented by Brescia) and Prosecco DOC (represented by Treviso) are at 45.5ºN  and Barcelona is 600+ miles south of Champagne at 41ºN latitude. The northern location of Champagne (close to the outer limit of accepted viable grape-growing zones) makes it difficult for grapes to ripen, resulting in acidic base wines which require the bubbles of the second fermentation to make them sparkle. Grapes in Franciacorta, for example, have no difficulty ripening and the resultant wines are richer than Champagnes of an equivalent sweetness level.

Climate

Climate is the average course of weather in a region over an extended period as measured by temperature, precipitation, and wind speed, among other variables. The climate of a grape-growing region will determine, to a large extent -- and all things being equal -- both the grape varieties that can be grown and the styles of wine that can be produced. That is not to say that these varieties cannot be grown outside of these environments; that is to say, however, that varietal typicity is compromised when these varieties are grown outside of their "zones."  Again, there are key differeneces between the regions.

Located as far north as it is, Champagne has the lowest average temperature of any French wine-growing region and, consequently, grapes do not ripen adequately over the course of a growing season. The northernmost outposts of the region are about 290 kilometers from the English Channel and are subject to oceanic influences. These areas experience regular rainfall but very little variation in temperature from season to season. As the traveler journeys south, however, continental climatic influences come into play to include: winter and spring frosts; summer sunshine coupled with violent thunderstorms; cold, wet weather in June; and hailstorms. Mean rainfall in the region is 700 mm.

Franciacorta is mild in the winter and hot in the summer. The climate is moderated by winds blowing in off Lakes Iseo and Garde which protect the region from the autumnal and hibernial fogs that threaten from the Brescian plains. Rainfall in the region is concentrated in the spring and fall.

Prosecco DOC wines are authorized for production in all of Friuli-Venezia Giulia and Veneto (provinces of Treviso, Belluna, Padova, Venezia, and Vicenzia) while the DOCG wines are authorized for production in Treviso.

In general, Friuli-Venezia Giulia has a humid, temperate climate which varies according to the landscape; areas to the north experience an alpine continental climate while those in the south experience a Mediterranean climate. The Alpine system protects the region from icy north winds but air movement from east to west causes low pressure systems which can bring summertime hailstorms and thunderstorms. Being open to the Adriatic, the region experiences Sirocco winds which can bring heavy rainfall. The climate is modified by the presence of the Adriatic Sea and the Alps resulting in warmer winter temperatures and cooler summer temperatures. Mean temperature in the summertime is 22.8℃ (73℉) and mean rainfall is 1524 mm (60 inches). Vineyards to the north and east lie above the level of the fog that flows in occasionally from the Adriatic and this allows the grapes to take advantage of the increased hang time to promote phenolic ripening. The diurnal shift is somewhat mitigated by maritime influences closer to the coast. There is a constant breeze known as "la bora" flowing in from the Adriatic and this provides great air flow in the vineyards as well as serving as a deterrent to fungal outbreaks.

Veneto has two major climatic regions: an alpine region -- characterized by cool summers and snowy winters -- and the mild winters and warm summers that are associated with the hills and plains. The overall region is protected from the severe northern European climate by the Alps, the foothils of which abut the area's northern flank. One of the most well-regarded Prosecco growing areas -- Connegliano-Valdobbiadene -- sits halway between the Alps and the sea and is blessed with a cool climate, bountiful sunshine, and generous rainfall.

Fully 95% of the Cava produced originates in Catalonia's Penedès, a wine region located about 40 kilometers southwest of Barcelona, and, as such, its climate will be the basis for our discussion of the DOs climate. Penedès is surrounded by the Monserrat range which provides a protective barrier from the heat and humidity of the Mediterranean as well as the cold winds -- levanter -- from the north and east. The climate is Mediterranean with annual temperatures averaging 15.5℃ (60℉) across the region but with slightly differing micro-climates within its three sub-zones. In Baix Penedès, the area closest to the coastline, elevation ranges between 0 and 250 meters and the temperature is milder, thanks to its proximity to the sea. In Penedès Superior -- 500 - 800 meters elevation -- there is greater rainfall than in the companion zones and a greater differential between maximum and minimum temperatures. Penedès Central (250 - 500 meters) experiences a mix of the Superior and Baix microclimates.

The grapes grown in Champagne would be expecetd to have higher acidity levels at harvesting than grapes from the other regions resulting in greater freshness in the wine. This increased acidity comes at the cost of less sugar resulting in higher levels of sugar added to the wines in order to attain end-state sweetness levels. Freshness levels would dedcline with movement towards the south.

Soils

The soil in Champagne is composed of massive chalk deposits interspersed with rocky outcroppings and covered with a thin layer of topsoil (mix of sand, marl, clay and lignite which requires constant renewal through fertilization. The chalk deposits in Champagne are finer-grained and more porous than other French limestone soils -- and have extremely high concentrations of the mineral marls Belemnite (younger and found higher up on the growing slopes) and Micraster (older and located on the valley floors) -- while the rocky outcroppings are 75% limestone plus chalk and marl. Chalk has excellent drainage as well as water-retention properties in that its micro-pores can absorb water during wet periods and slowly release it during drier periods. In addition chalk will also reflect sunlight and heat thus aiding in the ripening of the grapes. The chalk soil allows the vine roots to dig freely and deeply in search of water and nutrients and also retains a constant temperature year round.  One of the disadvantages of this alkaline lime-rich soil is that it prevents the uptake of minerals -- such as iron, copper, and magnesium -- which are needed for the prevention of chlorosis. The Côte de Bars region of Champagne has a Kimmeridgian soil of the same construct as the soils that underpin the vineyards of Chablis and Sancerre. This ridge of limestone and shellfish is nutrient rich and provides the optimal level of water retention and drainage for the growth of high-quality grapes.

Thanks to exhaustive zoning studies conducted in the Franciacorta region in the late 1990s by the University of Milan, a very clear picture of soil differentials -- and the contributions of each type to the finished product -- has been established. The figure below shows that the combination of landscape units (formations by geologic era) and soil types results in six distinct regional terroirs. The figure illustrates that the soil, vegetative productive, qualitative, and organoleptic characteristics of each terroir has also been identified. The details of those characteristics are contained in the table following.



The Friuli-Venezia landscape can be divided into four major areas: (i) the mountainous region to the north which includes the Carnian and Julian alps with peaks in excess of 2000 meters; (ii) a hilly area that is south of the mountains and along the Slovenian border; (iii) the central plain which is characterized by poor soil which has been made fertile through irrigation; and (iv) the coastal flatlands which is low and sandy to the west of the Isonzo River and rocky to its east. The soil in the region is calcium-rich marl and sandstone in hilly regions and clay, sand, and gravel elsewhere.
According to bottlenotes.com, Veneto has "silty, sandy soil with influences of clay and calcareous debris."

The soil in the Penedès region is a mix of limestone, sand, and clay with a chalky top layer preceding a layer of clay which in turn overlays a rocky base.

The regions have differing soil types with the Champagne region appearing to have a complexity of composition which is exceptionally beneficial for its grapes.  The thinness of the topsoil, and associated fertilization costs, plus the poor uptake capability regarding minerals are noted.  These have not been gating factors based on the history of the region and its wines.  In a future post in this series we will investigate how much soil matters to sparkling wine given (i) blending across soils in some regions and (ii) the degree of manipulation that is associated with construction of these products.

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The table below summarizes the points discussed in the foregoing.


The next post in the series will cover the production environments.  Click below to read earlier posts in the series.

Part I
Part II

©Wine -- Mise en abyme

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