The lowdown on the Mendoza wine region
June 4, 2017
Responsible for 70% of the wine made in the world’s 6th biggest wine-producing country, Mendoza is unsurprisingly Argentina’s most emblematic wine region. What’s all the more remarkable is that this is an area in a semi-desert with insufficient rainfall to keep vines alive. So why is Mendoza such a powerhouse of wine production?
Like most historical wine regions, Mendoza’s wine story began with the arrival of the Catholic church and its success hinged on its strategic location.
History and strategic location
It seems that vine material was brought via different routes into Argentina during the 16th century and, as elsewhere in South America, it was missionaries and monks who were responsible for planting the first vineyards and sowing the seeds of Argentina’s wine industry. And it was the Jesuit missionaries who discovered that the grapevines prospered most in the foothills of the Andes, in regions that included Mendoza.
Before the arrival of the Spanish colonists, the native population had built a network of irrigation canals to bring meltwater from the Andes and the new settlers made use of these canals to irrigate the vines and other crops, making them viable in an area that would otherwise have been too dry.
Thanks to its strategic location, just across the Andes mountains from Chile’s capital city, Santiago, Mendoza was ideally placed for trade with the neighbouring country. And so its wine industry began to flourish and soon became an important economic activity. Both secular families and the church produced wine, which was transported east to Buenos Aires and other Argentine cities, north to Bolivia and west to Chile.
However, the real boom for Mendoza’s wine industry came with the building of the railway connecting it to Buenos Aires in 1885, together with the arrival of new waves of immigrants, many from wine-producing areas in Europe, who brought their own vines and winemaking expertise. It is thanks to their contribution that Argentina produces such a diverse range of wines today.
Mendoza wine region in figures
- Area under vine: 159,137 hectares (2013, OIV)
- Latitude: between 32.9° and 33.2° degrees South
- Altitude: up to 1,700 metres above sea level
- Highest temperature in summer:29°C.
- Thermal amplitude: 14°C.
- Annual rainfall: 200 mm.(Source: Wines of Argentina)
The climate is continental with four defined seasons. Summers are warm with temperatures in some areas even reaching 40°C, while in winter they can plummet below freezing. I was there in early autumn and, as you can see from the photo, the vines were turning beautiful shades of yellow.
All sunshine and warmth
In warm, sunny areas like much of Mendoza province, grapes tend to ripen quickly. They accumulate lots of sugar in a relatively short time and, if not picked soon enough, begin to lose acidity. What does this mean? Well, there are two knock-on effects.
Firstly, it is the acidity that makes a wine fresh and gives it zing. A wine with low acidity can seem flabby and boring.
Secondly, it is the sugar in the grape juice that is converted into alcohol during the alcoholic fermentation. So the more sugar that has accumulated in the grapes, the higher the level of alcohol the wine will have. This is why wines from warm regions like Barossa in Australia or Mendoza in Argentina often have high levels of alcohol – they were made from very ripe grapes with high levels of sugar.
It’s quite hard for producers in such warm areas to obtain grapes that have just the right levels of sugar and acidity, while ensuring that the flavours and aromas have developed.
This is what Martin Kaiser at Doña Paula says about climate and the wines of Argentina:
“Most of the vineyards planted in our country are located between the warm and hot categories (Winkler IV and V). In warm weather conditions the temperatures never become a limiting factor for the grapes to reach a good level of maturity. This means that our wines are characterized for presenting a great fruity expression, being generally soft in mouth, with sweet tannins and very low average acidity levels.”
So, in recent years, producers in Mendoza- and elsewhere in Argentina – have been experimenting with altitude. Why? Because it’s cooler higher up. In fact, some of the higher areas in Mendoza fall into Winkler category III or even II. And at altitude, there is often a big difference between the temperatures in the day and those at night (known as thermal amplitude). All in all, if you plant your grapevines at a higher altitude, the grapes will ripen more slowly, enabling their aromas and flavours to develop fully, while ensuring that the sugar accumulation and acidity loss happen slowly. The result is fresher wines with higher acidity, potentially lower alcohol, and lots of ripe fruit and herbal aromas and flavours instead of jammy ones.
Whether on the plain or in the mountains, water is an issue. As in most of Argentina, Mendoza’s vineyards are located in the rain shadow of the Andes mountains – most of the prevailing winds come from the west and lose their moisture in Chile or crossing the mountains. So rainfall in the Mendoza area averages 200mm per year, not enough for a vine.
Traditionally, plenty of meltwater came down from the Andes mountains every spring to enable flood irrigation via canals. Argentine grape growers long supported flood irrigation as they believed that it helped stop the spread of the devastating vine-killing grub phylloxera. However, recent research has shown that this is not the case, as is detailed in this article by Julia Harding.
As in Chile, in the face of the harsh reality of receding glaciers, lower snowfall in winter and increased demand for water for industrial, agricultural and residential use, growers are having to consider reducing their water use. It was clear during my visit that many producers are switching over to drip irrigation, as shown in this photo from the Mendel winery.
The Mendoza wine region is often affected by tremendous hailstorms, which can decimate a crop. The seriousness of this problem was more than evident in the widescale use of netting, as shown in the photo. As I understand it, putting netting on growing vines is an awkward, expensive and time-consuming business, so you have to be really worried about potential damage to go to the trouble.
The Zonda wind that blows hot and strong in late spring and early summer can also affect flowering. Together with spring frosts, it can seriously affect the amount of grapes harvested, because if flowers are lost to frost or wind, there are fewer left to be transformed into grapes.
To give you an idea of how great an impact the weather can have on yields, in 2014, Argentina produced 15.2 million hectolitres (hl or 100 litres), while in the cool, wet conditions of 2016, production was down to just 9.4 million hl. In 2017, spring frosts did a fair amount of damage and yields this year are also expected to be down on the average level. Otherwise this has been a hotter than normal year on both sides of the Andes, resulting in earlier harvesting.
Getting down to earth
The soils are mainly alluvial, ie carried there by river flows a long, long time ago. They tend to be poor and free-draining, with stones, sand, lime, silt and some clay but not very much organic matter. Vines the world over thrive in such poor, well-drained soils. However, producers in Mendoza are no longer satisfied with just planting anywhere and are getting into the minutae of geology in search of soils that might bring an extra dimension to their wines. This is leading them to dig soil pits and do extensive surveys of the soil profiles in different areas, particularly in search of calcareous (limestone) soils formed millennia ago when the Andes mountains of today were actually part of the seabed.
Check out this excellent article by Martin Kaiser at Doña Paula, explaining what calcareous soils are, how they are formed and why they are of such interest to wine producers.
I’ll be coming back soon to the topic of geology, climate and terroir and how they influence wine style in a post about the Matervini winery.
Most vines are still planted on their own roots in Argentina. However, this is gradually changing, mainly because of the problems with nematodes – nasty, fast-reproducing roundworms in the soil that damage vines by eating their roots and can also spread other diseases. To combat this problem, many new vineyards are being planted with vines grafted onto nematode-resistant rootstocks.
The old-style pergola plantings are rapidly giving way to vines trained along wire systems, mainly vsp (vertical shoot positioning) as you can see in the photo.
This style of training makes it easy to control the amount of leaves in the canopy and thus create the best conditions for the clusters of grapes to ripen correctly, without fungal problems, uneven ripening or sunburn.
The warm, dry weather that is normal in Mendoza reduces the risk of fungal diseases.
Black varieties: Black varieties account for around 50% of the winegrapes grown in Argentina. Malbec is, of course, the star and I will be coverering this in a post soon. Mendoza also produces some excellent Merlot, Cabernet Sauvignon, Cabernet Franc, Bonarda and Tempranillo.
White varieties: Around 25% of all the vines grown in Argentina are white varieties. Mendoza particularly produces Chardonnay, Pedro Giménez, Sémillon, Sauvignon Blanc, Viognier and Chenin Blanc.
Pink varieties: Pink varieties are in decline but still account for some 25% of Argentina’s plantings. They consist of Criolla chica (that ubiquitous grape that is known as País in Chile, Mission in California and Listón Prieto in Spain) and Cereza (a cross between Criolla chica and Muscat of Alexandria).
Recent decades have seen significant change and modernization in Argentine wineries. This is partly because domestic wine consumption has fallen, meaning that producers have had to become more competitive in order to enter overseas markets and, as a result, 25% of Argentina’s wine production now goes to export.
Also companies and individuals from overseas have spotted the potential of Argentina’s wine industry and invested time, money and expertise in the country. Salentein in the Uco Valley is Dutch-owned, for instance.
Many wineries are now emphasizing quality over quantity in their quest for competitive edge.
This means lower yields in the vineyards, care over the timing of harvest, rigorous selection of the grapes and a more meticulous and controlled winemaking process.
Many wineries have switched to stainless steel – though epoxy-lined concrete tanks remain common – and some have invested in the ultra trendy concrete eggs in the quest to produce wines that offer something different.
Wine producers have traditionally protected themselves against weather-related losses by having different plots of lands in different areas and blending their wines, but more single-vineyard wines are now being made.
Where a bottle label states the variety, the wine must consist of at least 85% of that variety. For blends, any variety listed on the label must account for at least 20% of the blend.
A Reserva white or rosé wine must have at least six months ageing and a red Reserva 12 months, while Gran Reserva wines have twice as much ageing. Traditionally winemakers have used a lot of oak when ageing their wines – especially new French oak barrels, which gives the wines lots of aromas and flavours of toast and spices like cinnamon. This is still apparent, but there is also a move to produce fresher, more fruit-forward wines, with much less or even no oak influence.
Mendoza wine sub regions
Upper Mendoza River, including Luján de Cuyo and Maipú.
These areas are a little higher up (800 – 1100 masl) and have a cooler mean temperature. There are many vineyards here with a long tradition of quality winemaking, though the Uco Valley has taken over the limelight recently. I will be reporting on visits to three wineries in Luján de Cuyo: Mendel, Matervini and ReNacer.
The Uco Valley
This area is the one drawing all the attention, as detailed in an excellent article by Amanda Barnes.
So what IS so special about Uco? Well, the vineyards are located at altitude – 1,000m to 1600m above sea level – and, as discussed earlier, this makes for slower ripening. In fact, some areas in Uco are cool enough to be classed as II on the Winkler Scale. The combination of cooler weather, constant breezes, thermal amplitude, and very poor soils is making for some very exciting wines with plenty of body but high acidity. In a forthcoming post, I’ll write about my visit to the Salentein winery, a rather surreal site in the midst of a vast, open plain.
North and East Mendoza
These are low-lying, warm regions that produce lots of high-volume, entry-level wines, as well as some of superior quality.
South Mendoza, including San Rafael and General Alvear
This is a large area with a range of different terroirs and wines.
More on Mendoza
Visit reports to wineries in Mendoza – coming soon
Sources of information:
Robinson, J., 2015. The Oxford Companion to Wine. 4th Ed. Oxford: Oxford University Press.