What’s up with Altitude
Before we discuss any of the benefits of growing coffee at a high altitude, it is important to point out that altitude alone is an unfair scale of comparison. If you fail to consider latitude and climate you are missing the big picture. Temperature would perhaps allow for the best comparison, but constant fluctuation makes it impossible to measure. So altitude it is.
By growing at higher elevations, specialty coffee growers can produce harder beans. Smaller and denser than beans grown at lower elevation, these beans yield a more distinct flavor profile. They also have less air pockets, which allows for a more consistent roast.
Cooler temperatures slow the growth cycle, prolonging the maturation of the bean and allowing for more complex sugars to develop. Couple this with fast drainage, reducing the amount of water in the fruit, and the result is a more concentrated and nuanced flavor. The volcanic soil found at many of these mountainside farms never hurts either.
Another benefit to the cooler temperatures associated with higher elevation is disease resistance. Coffee leaf rust cannot survive below 59°F (15°C). Leaf rust is a devastating fungus that arabica coffee is particularly susceptible to and can wipe out an entire plantation. Additionally, the cooler temperatures protect plants from the coffee borer beetle (also called “la broca”). This beetle is the only animal that can feed solely on coffee beans and wreaks havoc through coffee crops around the world.
High altitude farming comes with disadvantages, too. Plants yield less fruit. While there is potential for higher quality beans, that only helps if the grower has the ability to sell to a specialty importer at a better price. The harvest is also later in the year. All those complex sugars take time to develop and that can translate to only one harvest per year. The longer harvest also means the plants require more care.
At the end of the day, altitude, and it’s relationship with climate, determine the type and varietals that a farmer can grow. Take a look at the map of coffee regions around the world and you will see how each area has adapted to grow the product that best suits their altitude, latitude and climate.