By Dereck Foster
For the Herald

When a local winemaker is asked to define themain or outstanding characteristic that identifies quality Argentine wines, more and more frequently the answer includes the enigmatic phrase vinos de altura. This can be loosely translated as high altitude wines, although the altitude refers more to the vineyards than to the wines themselves. What exactly does this mean?
By chance, the other day I came across an old cutting from a Chilean newspapper that ran a letter from a reader who enquired why it was that so much was said about the height of Argentine vineyards and not about Chilean vineyards. After all Chile had vineyards as high as many Argentine counterparts, but they were not mentioned as important factors in Chilean winemaking, he complained. He was right — and wrong at the same time. How come?
There are innumerable factors that gp into determining the character, and the quality, of a wine grape. The French have a name for it — terrroir — which about sums up the whole matter. Terroir covers innumerable factors that are essential for the obtention of good and great wines, and none is more dominant that the height factor. If we take a look at the wine map of Mendoza we soon note that with very few exceptions all the main wine areas are  the limits of 500m and 1500m above sea level. This ensures a sufficiently ample temperature differential between nights and days, a lack of atmospheric contamination, and a sufficiently ample period for ripening. These factors are all necessary for a wine to obtain the maximum required of colour, aroma and varietal character, all characteristics that are abundant in our good red and white wines.
So far, so good. Why, then, is it a fact that our vinos de altura are different to other wines that could, basing themselves on topographical grounds, also call them selves such? The answer is simple and basic: orientation and physical structure. Argentina is not the only wine country that can cultivate vines at interesting heights. Chile, Switzerland, a few areas of New Zealand, patches of Hungary and a few other scattered zones also break the 500m height barrier, but none produce wines with sufficient quality and attraction as to call attention. The answer is easy to understand once it has been pointed out. All the heights suitable for vine cultivation in Argentina are to be found in wide, open valleys where sun and air enter freely and temperatures reach extremes at semi-twelve hour cycles.
Other countries cultivate their grapes in narrow valleys, with steep inclines and protected from most daily sun by this factor plus facing away from the ideal direction. These closed valleys retard the natural development of the grape, especially when it comes to ripening, the scarce hours of sunlight being too brief to allow a good natural development. Apart from direct sun, natural luminosity is an important factor as well. The wider and larger the valley, the more and better light reaches the vines. These valleys — such as Uco in Mendoza and Cafayate in Salta, to give two leading examples — have been described by Ingeniero Alberto Arizu, head of the Luigi Bosca winery, as high altitude praries, and I think that his definition is about as accurate as one can get.
This matter of height, while most notable in Mendoza, is equally important all down the winelands at the foot of the Andes, from Salta to Patagonia. Indeed, it is the Andean range that causes the most important differences between Argentine and Chilean wines. While Mendoza and other vineyards start to enjoy the first rays of the sun as it rises in the east, Chile has to wait for the sun to travel west and surmount this gigantic barrier before starting to enjoy its essential caresses This accounts for the stronger herbaceous tones reflected by many Chilean wines — the Cabernets especially — in comparison with those of Argentina. Only superior technology has kept the two industries on a semi-parallel path, but now that local Argentine technology is finally catching up, this equilibrium is slated to vanish.
In the height stakes there is one area in Argentina that bears no comparison with any other in the world. I refer to Cafayate.The Calchaqui Valleys, of which Cafayate is the prime exponent. Here height deserves a capital H. Starting with a modest 1700m around Cafayate city itself, we can visit vineyards and wineries that, in one case, just break the 2400m mark. This is the Colome winery which boasts a long and noble life as a leading exponent of the region. Although the iconic grape here is the Torrontes, new ideas and technology have begun to produce some quite incredible red wines of a very characteristic and world class character.