Italy, geology: Italy is essentially a mountainous country with two main mountain ranges: the Alps, stretching from east to west in the north, and the Appenines, generally much lower in altitude than the Alps, running right down the middle of the country north to south. These two mountain ranges account for almost 35% of all Italian territory. As another 40% of Italy is made up by hillside slopes leading up to those mountains, it becomes apparent that there is very little flat land in Italy. The lack of plains in the country is one of the reasons that over 60% of Italy’s cheeses are made from sheep milk, as there just is not enough room for cows to graze, save in the north. However, hilly topography is the best for viticulture, as grapes that make the finest wines rarely, if ever, come from flatland vineyards. The many different altitudes, exposures, microclimates, and soils on which vineyards are planted, help explain Italy’s unique ability to produce quality grapes and wines. Especially important are the geological characteristics of many Italian wine terroirs, since these features are almost non-modifiable, their geology and microclimates changing slowly in time, over the span of millennia. In contrast, viticulture and winemaking are dynamic entities that undergo faster changes in time—changes which are meant to bring about improvements in wine quality. However, often such innovations prove to be deleterious in the long run, for instance the uncontrolled planting of international grapes everywhere in the country, or the indiscriminate attempt by less talented producers at making ‘natural’ wines. Unfortunately, these producers only succeed in making unpalatable if not downright faulty wines.
Soils form as the result of glacier formation and retreat. For example, in the case of the Alps, their soil is the result of over 100 million years of ongoing deposits and retreats, or so-called tectonic movements. Older soils have forcibly different origins, diverse mineral concentrations, different stone size, and are compact in a different way compared to more recently formed soils. It is these differences that determine which of the country’s areas will be more or less suited to quality viticul- ture. It follows that because of the glacier activity in its advancement and retreat mechanism, some landscapes are going to be characterized by gently rolling hills while others will be marked by steep mountain slopes. Depending on the presence or absence of volcanos, some soils will have a volcanic origin instead of a sedi- mentary one. The former will therefore most likely have higher potassium contents while others will be characterized by high limestone, sand, clay, or granite contents. As an example on the importance of minerals in the soil, it must be noted that soils rich in basalt are rich in potassium. As these are warm soils by definition, grapes grown in such soils tend to give fuller, bigger bodied wines.
In Italy, soil composition changes quickly from site to site, even those in close proximity with one another. A common saying among Italian farmers is that in Italy’s soil changes occur “from palm to palm”, meaning that walking even small distances within a vineyard will reveal many different soils. Ultimately, Italy has vineyards located in just about all sorts of possible topographical situations, because of its greatly mountainous habitats and varied geology. After all, anyone who has taken a trip to Italy has witnessed the presence of vineyards in just about all possible ecosystems, from water edges in seaside locations, to lakeside scenarios and high mountain landscapes. Indeed, some of the highest vineyards in the world, such as Valle d’Aosta’s Prié Blanc vine- yards are located as high up as roughly 3500 feet (1000 metres) above sea level.
See Ian D’Agata, Native Wine Grapes of Italy (University of California Press, 2014).
Italian Wine Unplugged (Positive Press, 2017), p.20-21.