Fine coffees grow at about 3,500 feet (1,000 m.) in altitude to over 6,000 feet (1,800 m.). Some rare exceptions exist: Hawaiian Kona is so far north of the equator that coffee cannot be grown higher than 2,000 feet; it is simply too cold.
Altitude has a powerful effect on a coffee’s flavor profile. Flat plains can subject coffee plants to greater heat, less ventilation and less diurnal temperature contrast. Coffee beans and their surrounding fruit tend to ripen more quickly and develop smooth, duller, sometimes earthier, flavor tones than coffees grown at higher elevations. Very high altitude environments are subject to greater, rainier cloud cover interspersed with very intense periods of sun and high diurnal temperature contrast within an ideal range of 50˚ F to 85˚ F. In mountain valleys such as Antigua, Guatemala, temperatures can plummet at night.
Coffee quality is often graded in part by altitude. As an example, there are eight classifications according to elevation in Guatemala starting at Good Washed, at 2,300 feet, to the highest, Strictly Hard Bean (SHB) at over 5,250 feet. Beans growing at lower levels tend to be softer and less dense; in storage, they lose their flavor more quickly than harder higher grown coffees. As a general rule, traditionally, the higher the elevation the better is the potential premium paid to the farmer. Higher elevation coffees exhibit greater floral and bright fruit flavors, with greater liveliness. High altitude usually also means more difficult access and maintenance of roads, greater difficulty planting, maintenance of plants and harvesting as well as less yield per tree.
The highest grown coffees are not necessarily always superior to those grown at moderately high altitudes. It also depends on latitude, the most famous example being Kona, Hawaii which is very far from the equator and where 2,000 feet elevation is the highest one can grow coffee, barely. Most Kona coffee grows far below. Many very fine and delicate Brazils are also far from the Equator. Bill McAlpin of La Minita in Costa Rica chooses very carefully hand selected beans from a moderate to very high altitude to give his coffee extra body and smoothness. Also, while the finest Ethiopian Yirgacheffes are grown in the vicinity of 6,000 feet and have extraordinary floral aromatics they do not have the intense acidity of the great blackberry-laden, high altitude Kenyas, Ethiopia’s neighbor to the south. This may be due to soil differences and/or the radically different varieties of Arabica coffee grown in these two countries.