Definition - What does Elevation mean?
Elevation reffers to the altitude at which grapes are grown. There is no exact definition for high-altitude or low-altitude wines. However, when vintners consider which grapes to grow where, these details determine how the vines will be trellised, and the elevation can play a major role. The higher the vines, the more direct sunlight they will get. Evenings and some days are cooler during the growing season, and the density of the air differs from lower areas. Inaccessibility to water also plays a vital role.
Wines are not necessarily "different" or better in higher altitudes, however, they are often much heartier and consist of higher concentrations of aromatics, textures and flavors as the grape adapts to harsher conditions. These elements are found in the skins, which impart much of the characteristics into the wine.
WineFrog explains Elevation
While a vineyard at 1,500 or lower might not be a considerable elevation to alter the way a vineyard should be cultivated, a vineyard site sitting at 2,000 feet above sea level or more is one that should be managed with more detail. Some of the world's most famous high-altitude vineyards are found in Mendoza, Argentina and the highest in the world from Salta. However, in the United States, wines from Colorado are also making their mark in high-altitude wines.
When vines are cultivated at high altitudes, the conditions are much more harsh. The water table is often out of reach of their root systems, and annual precipitation is often much lower. In high elevations, the grapes are also within close proximity to the sun's rays. If the canopy and vines are not managed properly and the vines are not given water at crucial moments during the season, grapes can burn and shrivel. However, the grape vine has the innate ability to adapt naturally. This typically involves mutation and thickening of the skin and lower pulp concentration. A grape such as this requires less energy and can survive the whole season up until harvest.
The high elevation for growers is often a desirable one for its natural diurnal temperature ranges, meaning that the grapes have a significant amount of sun and heat during the day-time needed to produce sugars and much cooler temps (often a 15 degree plus temperature difference) in the evening, which is crucial for maintaining balance in acidity and the maturation of aromas, flavors and textures.