No two winemaking regions are the same – indeed, there can be myriad differences between two vineyards in close proximity to one another. What makes every wine unique is its terroir, a French term meaning ‘a sense of place’. While there’s no official definition of terroir, it’s a widely accepted phrase among wine aficionados when it comes to describing a wine’s particular qualities, and generally hinges on the combination of several elements of wine growing, including temperature, climate, soil composition and topography (things like slopes and elevation).
Here’s how these factors can impact the final product.
Temperature
When we talk about temperature as a component of terroir, we mean average temperatures over a long period of time – not the specific weather conditions affecting individual vintages, which may see hotter or colder growing seasons compared to usual (although the impact of climate change can’t be ignored – more on that later).
In warmer regions, grapes ripen more easily, resulting in lower acidity, higher sugar levels and darker colours. You’re more likely to find bolder, fruitier wines in a warm region than in cooler areas, where grapes have more difficulty ripening. Here, you’re more likely to get higher levels of acidity, lower sugar levels and a lighter body, resulting in dry, refreshing wines.
Climate
While temperature is a key factor in terroir, the overall climate needs to be taken into account as well, as factors such as rainfall, humidity, wind, frost, hail and sunlight play a major role in the development of a wine.
Sunlight is necessary for grapes to produce sugar, but too much can cause sunburn. Rain is also vital for vine growth – but too much can cause disease and dilute flavours. Strong winds, meanwhile, can slow the maturation of a grape, which is not necessarily a bad thing, but a factor that will certainly affect the outcome of the wine in one way or another.
The climate of a region is generally determined by geographical location, although smaller sub-regions and even individual vineyards can experience their own microclimates, which result in particularly unique wines.
Again, these are all elements taken into consideration over the long term. When speaking about a wine’s terroir one considers the climate overall, rather than in specific vintages.
Soil composition
The type of soil vines are grown in can have a profound effect on the flavour of a wine, as it’s responsible for the nutrients they require to prosper. Interestingly, however, soils used for grape growing are unsuitable for almost all other types of agriculture.
Vines can be grown in a wide variety of soils, including sand, clay, pebbles and even rocks – with dozens of combinations in between. In addition to the nutrients within, soil provides vital drainage, with some vines liking extra moisture and others disliking having ‘wet feet’. The colour of the soil also affects its ability to absorb or reflect the sun’s heat.
All of these factors combine to create a distinctive foundation from which the vines can grow, contributing further to a wine’s unique terroir. Generally speaking, though, sandy soil vineyards tend to produce drier, more elegant wines, while clay-based soils usually produce bolder, more structured wines.
Topography
There’s more to the location of a vineyard than its position on a map. Topography takes into account slope, altitude and nearby physical features, which all have a significant impact on terroir.
Steeper slopes, for example, drain well and may get stronger sunlight, while its aspect will affect just how much sunlight vines stand to receive. Higher altitudes, meanwhile, usually means chillier nights, which will result in more elegant, age-worthy wines.
Nearby physical features such as lakes and mountains can also have a significant impact on vines. Lakes and other large bodies of water can provide a moderating influence (keeping the area warmer in winter and cooler in summer), while mountain ranges can offer protection against elements such as wind.
The impact of climate change on wine
Terroir can change over time, both as a result of man and nature, but right now we’re witnessing a major shift in terroir around the world thanks to climate change. While climate change is generally associated with a rise in average temperature, the consequence for wine growing comes in the tumultuous weather activities that accompany it – drought and flooding, for example. And given that many crops – vines included – have relatively narrow margins for optimum production and quality, even small changes could bring about major challenges.
For some regions – particularly cooler climates such as northern Europe and the UK – climate change may well prove a boon to winemaking. For others though, adaptive measures will be necessary. Some steps already being taken include introducing new grape varietals, modifying vineyard orientation and irrigation, and even marketing new regional identities.
It’s not clear yet exactly what climate change will mean for the wine industry in the long term. In the interim, however, it will certainly lead to new viticulture offerings and therefore an even more expansive definition of terroir.
