Tell Me About Terroir!
Let’s talk about each of these concepts in more detail…
First you should understand climate vs weather. “Weather” describes the environmental factors that persist for a very short time (“the weather is cold and rainy today”), whereas “climate” describes the environmental factors that generally persist in a region over time (“the climate in Napa Valley is known for having warm dry summers and cool moist winters”). Certain climates are ideal for grape growing while others not so much.
Did you know that grapes can only be commercially viable for wine when grown between the 30 and 50 parallels? Much outside those ranges and the temperatures are either too hot or too cold. The ideal climate for grape growing includes
Warm summer days (70-85 F) to allow photosynthesis. Too hot and the vines go into a self-preservation mode and shut down some physiological processes; they can even be damaged.
Cool nights to allow the vines to cool and breath.
Enough wind to support pollination but not so much that it causes damage.
Enough humidity to keep the plants cool but not encourage fungus growth.
Access to moisture but not so much as to cause the flavors of the grape to be diluted
Grape vines are grown in a variety of soils the world over from clay, chalk, gravel, silt, marl, limestone and more. Regardless of the type of soil and the size of the soil particles (clay is very fine, sand slightly courser or gravel larger pieces - they each influence temperature and water retention and are often all present in a soil in varying ratios) two generalities persist: first we want rather infertile soils and second we want dry conditions in the topsoil. In other words, we want the vines to “struggle”.
The harder it is for the roots to find moisture, the further down into the soil they go - that means they
have access to more layers of subsoil to pass through with more complexity and interesting effect on the wines,
are less susceptible to pests, disease and damage that can occur when roots remain only in the topsoil,
have more access to a supply of water that is consistent,
have access to subsoils such as limestone and chalk, which are good for water retention during dry spells but also good drainage during rainy seasons.
And the harder to find nutrients, the more the plant concentrates flavors in the grapes and the more developed the flavors in the wine are. Very fertile soils cause vines to produce an over abundance of leaves and shoots, diverting the plant’s energy and sugars away from the fruit.
Geography refers to how far from the earth’s equator the grapes are grown (degrees of latitude) , the elevation, topography, aspect and proximity to a body of water.
We already discussed how the degrees of latitude (a geographical descriptor) impact the climate, but what of elevation, topography, aspect and water bodies? These factors all influence how successful grapes can be grown in their particular locale and all the aspects are interrelated.
For example, elevation effects the intensity of the sun’s rays, the temperature fluctuation night to day, the way rain water and moisture runs off, the access to (or not) cooling bands of fog, cloud cover and more. Because successful grape growing relies on warm to hot daytime temperatures with access to sunlight, and cool nights you can see how elevation is important. But vines can do very well at both higher and lower elevations - it all depends on how the other factors come together to satisfy the warm sunny day and cool night requirement.
The same applies to both topography (land structures) and aspect (the direction that a hillside faces). For example, a south facing hill receives more direct sunlight than a north facing one (in the northern hemisphere anyway), which is highly desirable in a cold climate. However in warmer climates, it may not be ideal to increase the sun exposure. Furthermore, there is often talk in wine circles of “valley fruit” vs “mountain fruit”, this refers to the topography’s influence on the wine. Mountain fruit often struggle a bit more, have less access to water, produce less consistent fruit, are harder to farm and generally produce more tannic and complex wines. Valley fruit are the opposite and often produce more lush and fruit forward wines.
But the proximity to water is an interesting conversation. 🥰 This isn’t just about moisture: rain, fog and mist. It’s about how bodies of water help to maintain more consistent temperatures throughout the day and throughout the year. If you look at a map of your favorite wine-producing region, you’ll nearly always find that the vineyards are situated near an ocean or a river or lake.
How Terroir Effects Winemaking
Remember that our definition of “terroir” doesn’t limit us to just where the grapes are grown but includes where the wine is produced? While this is important for all wine production I want to give one very poignant example of how terroir effects the wine even after the grapes are harvested! Sherry is a type of wine (both sweet and dry) that is associated with the Andalusia region of Spain, in particular it hails from the winemaking region of Jerez on the southern coast.
Some sherries produced in this region (fino, manzanilla) are aged in a method referred to as “biological” aging, where the sherry is aged for years in oak barrels under a layer of “flor”, regionally specific yeast that protect the wine from oxygen while chemically reacting with the phenolics of the wine and influencing its flavor. The specific yeasts involved in this process and conditions to support the flor growth are not supported anywhere else in the world. In fact the import given to terroir in the area is even distinct enough from town to town in Jerez that “Fino” sherry is produced in one town while “Manzanilla” is produced in the exact same way under different flor from a neighboring town. Here the terroir is so intimately influencing the flavor and outcome of the wine during the winemaking process as to require labeling it as a different wine altogether.
While this is one example, you can extrapolate to see how the regional climate, moisture levels and natural flora present even after harvest can have a subtle or profound impact on the wine in the end.
Old World v New World Ideology
A conversation about terroir would not be complete without touching on the topic of old world vs new world ideology. In fact, I probably should have started off with this discussion. The definition of “old world” vs “new world” refers to both a geographical distinction as well as one of philosophy and wine making style. Yet the lines are blurred. Geographically speaking, “old world” refers to European grape growing regions, “new world” to nearly everywhere else: the Americas, South Africa, New Zealand, Australia, etc. This is because the history of viticulture in Europe dates back much further than it does in other areas. The term “old world” has also become synonymous with a style of winemaking that favored the influence of the terroir with minimal intervention by the winemaker. Whereas “new world” is now often used to refer to a philosophy that the winemaking techniques have more influence on the end product than the terroir. In practice both old world and new world winemakers today respect both the influence of the land and the maker on the wine.
And there you have it! I hope you understand terroir better than you did before!