The warm air currents from the Pacific Ocean that reach through the canyons formed by the Nariño mountains, together with the sunlight that touches the deep valleys are what allow for coffee production at the higher altitudes of the Andes of Nariño. The Southern Trade Winds, blow from the southern hemisphere north, and also impact the Nariño coffee region by affecting its temperature. These masses of air are what make the production of Arabica coffee viable at altitudes that easily surpass 1500 masl (4921 ft.) and often up to 2300masl (7545 ft.).
The soils in the Nariño Coffee Region are made up mainly of volcanic ash in different stages of evolution. The western region surrounds the Galeras volcano, whereas the northern region is situated around the Doña Juana volcano. Despite minor differences, experts agree that the soils are made up of Andisoles and Oxysoles, which contain a large quantity of organic material and provide a high percentage of the basic nutrients needed for coffee production. The depth of the soil is variable; its texture, sandy; and it allows high phosphorus fixation.
The geographical location of Nariño, its wind patterns generated by the topography and its deep valleys also influence the average temperatures and thermal range (Graphic 3) that the coffee trees are subjected to, which are relatively lower than those in most other parts of the Colombian coffee producing areas. Thus, the fact that the trees are not able to enjoy ideal conditions for their development, they set into action certain “defence mechanisms” by inducing metabolic processes that directly affect the particular coffee taste attributes.
Graphic 3. Average Temperatures in the La Unión Coffee Area – Nariño.
Because of the lower temperatures, the plant does not develop to its full capacity at the same rate as in other areas. A coffee plant planted in Nariño can be 1.40m (4.5 ft.) tall in three years, whereas, planted in a region where temperatures are higher the same plant can reach a height of 2m. Coffee plants in Nariño also produce less—sometimes 50% less—than trees planted in other areas of Colombia. Clearly, the trees in Nariño regulate their energy; firstly, in order to stay alive in such conditions, and secondly to grow and give fruit, which is another reason why the production of Café de Nariño is limited and its price higher.
The lower temperatures also explain why coffee plants in Nariño can take up to 36 weeks in developing coffee cherries, four times more than trees in most other areas of Colombia. This longer period allows the cherries to develop more homogeneously, with denser seeds, and to accumulate more sugar, which givesCafé de Nariño one of its most important attributes: its sweet taste. These and other compositions are present to greater or lesser extents thanks to these phenomena, as is illustrated in the biochemical properties of Café de Nariño and the Coffee Journey - Virtual Trip to Origins®