The Uco Valley: Where Diverse Terroirs Work Their Magic

BY JOAQUÍN HIDALGO | SEPTEMBER 07, 2023

If you’re the kind of wine lover who is always on the lookout for the next surprise, then the Uco Valley is the place to be right now. In this report, you’ll learn why. If there’s a region in South America that encapsulates the spirit of winemaking precision and creativity, it’s this unusual, alluring valley.  

Gualtallary is the highest region in the Uco Valley, wrapped like a horseshoe around one mountain and towered over on all sides by more. In the photo, we see the southern face of the Plata Mountain in the background, behind the Bemberg vineyards, which are planted at 4,430 feet in an area known as Albo.

The Uco Valley is unusual because its 60-mile stretch only has one mountainous side: the western slopes where the Andes reach up into the sky, with some of the range’s peaks breaching 20,000 feet. However, to the east, except for a few gentle hills, the valley is hardly closed off. It is alluring because, in addition to the stunning landscape, the valley’s modern wines and vibrant winemaking movements are a true reflection of the creativity to be found in the local culture and terroir. Or, more accurately, terroirs - plural.  

An hour’s drive south of the city of Mendoza, the Uco Valley is the fastest-growing wine region in Argentina. Once a remote outpost with 8,000 hectares under vine back in 1990, today, vineyards span 29,000 hectares, a rate of expansion you won’t find anywhere else in the country. It’s a remarkable story of viticultural development that occurred especially fast between 2002 and 2022 when two-thirds of the current surface area was planted, and investment opened up new horizons for the region.   

To get an idea of the diversity here, you can try a simple exercise: compare two Malbecs from the Uco Valley. One might be ripe, indulgent and rich, while the other could be fresh and juicy, but with a leaner structure. Even within the same area and varietal profile, several different determining factors are always in play. This is a territory with the potential for great discoveries, but also one where it’s easy to lose your way and end up with a wine quite different from what you were hoping for. It can be difficult to get your bearings.     

Because producers are aware of this, they’ve worked hard on charting and classifying the Uco Valley. Today, every vineyard has its own soil charts and pits, while meteorological stations and studies have multiplied to satisfy the increasingly curious minds of winegrowers. These include maps, comparisons and experimentation with new, more specific styles. Terroir experts such as Pedro Parra, Lydia and Claude Bourguignon and Guillermo Corona have played a key role in the valley’s rise, and the fruit of their painstaking work is coming out in the glass.

I tasted about 650 wines from the Uco Valley for this article, almost all of them reds. In my earlier white report, I tasted another 400 valley whites. Working through those samples was a challenge as trends are still taking shape. That is what made those tastings even more interesting. In addition to a handful of world-class wines with exemplary expressions and concepts, many of the Uco Valley wines are beginning to settle into a range of stylistic and terroir-based categories.

If you’re looking for reds with a raw, primary character and good acidity, head to the higher vineyards in Gualtallary and San Pablo. If you’re hoping for more volume, texture and juicy energy, turn your eyes toward Paraje Altamira, Pampa El Cepillo, Los Chacayes and Vista Flores. Meanwhile, broader, more velvety reds with mellow tannins and an expansive flow are to be found in La Consulta. And that’s just a sample of the different characters the valley has to offer.

Three Terroirs in the Uco Valley

In-depth studies of the terroir have allowed for the identification and classification of several different regions within the valley: Paraje Altamira development (which I wrote about in 2019) was an excellent example. It was followed by San Pablo, Los Chacayes (which is currently undergoing further examination), Pampa El Cepillo and Cordón El Cepillo, La Consulta, El Peral and the most complex and promising of them all: Gualtallary.

These names didn’t really exist a decade ago. Not in the world of wine, at least not legally. Work differentiating heights, climates, soils and potential styles within the valley resulted in the emergence of officially sanctioned Geographic Indications. Since 2013 – when the first version of Paraje Altamira was approved – a dozen Geographic Indications have been declared in the Uco Valley in order to make it easier to know precisely where a wine comes from and what its resulting character is likely to be. And the labels bear them proudly.  

In this report, Paraje Altamira, Gualtallary and Los Chacayes account for about half of the bottles tasted. Let’s take a look at the latter region first.

Los Chacayes is located at the center of the Uco Valley in front of Cordón del Portillo ridge, which can be seen in the background with the Arroyo Grande Valley in the middle. Recently redrawn, the soils of Los Chacayes were formed by the Arroyo Grande River. This vineyard, set in the foothills, belongs to Los Arbolitos.

Los Chacayes’ name is derived from a political demarcation in the heart of the Uco Valley, where the surface area under vine has risen from less than 100 to 1,900 hectares in the past 20 years, all at a height of between 3,200 and 5,400 feet above sea level. This expansion ran through several different temperature ranges: for every 500 feet higher you go, the average temperature descends a degree centigrade. So, within a distance of nine miles, you can go from a mild area to a cool one—the equivalent of traveling from the Rhône Valley to Champagne.  

In terms of soils, the Arroyo Grande River is the main vector, flowing down from the granite-rich mountains of the Cordón del Portillo and changing the soils quite drastically as it goes from large boulders in the higher areas to fine gravel with sand and lime lower down. Approved as a GI in 2017, today, its boundaries were revised to better reflect the make-up of the soils and finally were redefined in August 2023. I find that Los Chacayes produces generous, intense and free-flowing reds in the heart of the region, such as the 2020 Malbec Terrazas Parcel Lican or the 2021 Malbec Bianchi IV Generación, but in the areas higher up, the palate gets thinner while maintaining the energy, as is true of the 2021 Malbec Riccitelli, the 2021 Malbec Andillian or the 2021 Malbec Buscado Vivo o Muerto El Manzano.

Gualtallary is a similarly complex equation. It’s a large district with 2,500 hectares under vine, all planted since 1992, between 3,200 and 5,400 feet, although, if someone were brave enough and had access to water, they could go as high as 6,600 feet. The key things one needs to know about Gualta – as producers call it – is that the Las Tunas River flows through it, and much of the land is scattered with boulders. Within its boundaries, one finds at least five different kinds of soil at different altitudes: pure sand or gravel (lower down), soils rich in compacted calcium carbonate and sand dunes (higher up) and soils to the south that have been washed bare by the river. This is why Gualtallary is the most important region in the sector and why its producers are giving it special attention. Some are even discussing the prospect of sub-divisions such as Monasterio in the Sierras de Gualtallary area, Río where the river flows, and an area rich in calcium carbonate known as Gualtallary Albo.

A Malbec from the Monasterio area will likely have a distinctively chalky character and a restrictive palate (2021 Malbec Raquis, 2021 La Craie Per Se, 2021 Malbec Adrianna Vineyard River, 2021 Malbec Primeras Viñas Gualtallary), while those in the Albo area (2021 Malbec Luna Llena, 2019 Pionero, 2020 Malbec Doña Paula Selección de Bodega) will have the same chalkiness but greater volume. Lower down, in the areas where the gravel is washed clean by flooding, shallow soils and higher temperatures ensure greater volume, structure and alcohol (2021 Malbec Sophenia, 2020 Malbec Rutini Single Vineyard).

Paraje Altamira is a little further away from the peaks. Its soils were formed by the Tunuyán River, whose alluvial fan defined the region's boundaries. The photo shows the Piedra Infinita vineyard at Zuccardi Valle de Uco last autumn.

Where altitude is a decisive factor, and the position of the slopes determines the soil makeup in the two regions mentioned above, Paraje Altamira is quite different. The region has 2,700 hectares under vine at similar heights of between 3,200 and 4,100 feet. That means that the climate remains consistent; it’s the soils that vary. Alluvial in nature, they range from bare rock to areas rich in calcium carbonate. When producers manage to isolate a single vein, they can be confident of producing a specific type of profile. One example is the Jardín Altamira vineyard belonging to Altos Las Hormigas, which is designed and planted along one of these veins. Of course, grapes can also be classified during the harvest. In the glass, wines from Paraje Altamira tend to offer a fairly chalky palate (when they come from vines planted in calcareous soils), good fat (when they’re from soils with bare stones), a juicy flow and consistent energy (2021 Malbec Meteora, 2022 Mabec Concreto, 2021 Blend Gran Revancha, 2021 Malbec Reserva HD, each of which has its own distinctive character).

For the curious consumer, the Uco Valley promises to be an inexhaustible source of entertainment. You can seek out and combine different terroir variables, especially in wines made by reliable producers, comparing and contrasting the connection between the different wines and their places of origin. As the sense of place grows more prominent, regions are able to define flavor profiles that can even be applied across different varieties. Today, the Uco Valley is a funhouse for inquisitive palates, a creative hotspot producing some of Argentina's best and most modern wines.

The Drop that Revolutionized the Valley

Some distance from all the modern commotion, lower down in the valley, vineyards have been grown since the nineteenth century in locations where water could be channeled for irrigation. Two areas in particular stand out: La Consulta in the south and Tupungato and the surrounding land in the north.

La Consulta is an agricultural area. It has been planted since the early twentieth century and boasts 100-year-old Malbec vineyards, while its neighbor Paraje Altamira was first planted in 1950 before the current boom. I like to think of La Consulta as a heritage area with old vines and flood irrigation in the middle of a green oasis full of poplar and willow trees lining the irrigation canals. This is also true of El Peral and San José in Tupungato, where there are old vines, especially Sémillon, since the area is higher and cooler.

This schematic map of the Uco Valley shows the main Geographical Indications of the region, as well as the rivers that shape the main types of soil. While Gualtallary is the largest and crosses the greatest range of altitudes, Los Chacayes, Paraje Altamira and La Consulta each offer a single temperature zone. The combination of altitudes and soils defines the terroirs of the Uco Valley.

In 1991, The arrival of drip irrigation changed this bucolic environment. After that, it became possible to plant large, virgin surface areas as one no longer had to level the terrain and could use well water. Technology is responsible for the modern development of the Uco Valley, the increasing height of the vineyards, the pushing of climatic limits and the exploration of new types of soil. The key to the creation of the valley as it is today also came with major investment. Following in the footsteps of Bodega Salentein, the first monumental winery in the region, which opened in 1998, the Uco Valley now also possesses a series of winery buildings notable for their architecture, such as DiamAndes, Monteviejo and Zuccardi Valle de Uco.

Significant investment also saw a surge in wine-related projects such as Tupungato Wineland in the north, Casa de Uco, The Vines and Los Arbolitos in Los Chacayes, which supply many of the wineries of Mendoza with grapes. More recently, projects offering high-end tourism, hospitality and restaurant experiences have appeared. Hotels at Casa de Uco and La Morada de Los Andes are accompanied by several lodges such as The Vines (or those being built at Andeluna), as well as restaurants such as Piedra Infinita and Siete Fuegos, meaning that you can now spend days touring the vineyards and estates in a manner similar to major wine regions elsewhere in the world.

Today, the Uco Valley offers a vast panorama of wines and related enterprises that have managed to establish the region’s reputation within a relatively short period of time. But there’s still plenty more room for development in the future, a trend likely to be driven by an ever more precise winemaking culture. 

© 2023, Vinous. No portion of this article may be copied, shared or re-distributed without prior consent from Vinous. Doing so is not only a violation of our copyright, but also threatens the survival of independent wine criticism.

You Might Also Enjoy

The Age of Mountain Whites: Enjoying the Altitude, Joaquín Hidalgo, July 2023

The 2023 Harvest in Argentina: Throwing Out the Playbook, Joaquín Hidalgo, May 2023

Luján de Cuyo: Old Vines and a Patchwork of Soils, Joaquín Hidalgo, January 2023

Argentina: Making It Work with Resilience and Stylistic Ingenuity, Joaquín Hidalgo, November 2022

A Revolution of Place: Argentina Classifies Its Terroirs, Joaquín Hidalgo, September 2019