Terroir is a French word meaning “land” or “earth”. In the context of wine, it has been defined as the specifity of a place, although these days the ideas on this are converging and it has lost its sense. Wine tasters usually include concepts such as the climate, the aspect, the soil and anything else that can differentiate one vineyard’s area from another.
According to the OIV, terroir refers to “an area in which collective knowledge of the interactions between the identifiable physical and biological environment and applied vitivinicultural practices develops, providing distinctive characteristics for the products originating from this area”. The term includes specific soil, topography, climate, landscape characteristics and biodiversity features.
So then, what is terroir? Essentially, there are some key concepts that must be considered when talking about it:
Climate: the climate of a specific site refers to the weather patterns that are common during a significant period of time. Parameters that are taken into account include average rainfall, length of the growing season and continentality. Although there are several climates, only four are of interest to viticulturists: Continental, Maritime, Temperate and Mediterranean. The climate of a region influences both the grown grape varieties and the style of wines produced. The weather is also an important factor, since these conditions determine the quality of the grapes and the wine of a vintage.
Topography: this term refers to the location of a vineyard and its surrounding properties. It can include factors as the altitude, aspect or terrain, not just the vineyard’s position on the map. For example, the slope of a vineyard affects the amount of sunlight the vines receive and also determines how well the site drains, while the altitude has an impact on the temperature. This is a key consideration since cooler areas are appreciated by their capacity to develop complex flavors and retain acid compounds. Geological features, large bodies of water and other flora also affect how a wine from a concrete vineyard tastes –lakes provide a moderating influence on temperatures while mountains offer protection against wind or rain-.
Soil: the type of soil has a great effect on the flavor of a wine: they provide the necessary nutrients, direct the supply of water the vineyard needs and alter the existing temperature within it. It is important not to ignore the microbial community that inhabits the soil. It has a great impact on the grape’s health and its taste and flavor during fermentation, too.
These communities of microorganisms –fungi, yeast and bacteria– play an important role in soil productivity as well as in disease resistance developed by the vine. The impact of the microbiological component of terroir contributes to the sensory regional distinctiveness and the wine style of the winery. The microbial community of each vineyard is an essential factor that distinguishes it from the rest.
As a conclusion, we can state that terroir isn’t just the climatic conditions, the altitude of the vineyard or the type of soil. It is the combination of all the components that work together to produce grapes and wine. Understanding the terroir and its influence on the vineyard development and wine production is key to preserve regional biodiversity and product identity, where microorganisms also play an essential role.