Origin // Terroir
There are many facets of a coffees geography and origin that have a profound impact on the flavour characteristics in the cup; soil quality, elevation, micro climates. Terroir, a term traditionally applied to wine, is used to describe these specific geographic traits that makes coffee unique to the place where it was grown. Furthermore, one coffee farm can have more than one Terroir depending upon the topography and micro climates that may be present on a particular farm. For example, one section of land may receive less direct sunlight allowing the coffee to mature at a slower rate and produce a superior coffee to the rest. It is becoming more common for farmers to separate the different sections of their farm into lots based on elevation, cup quality and varietal.
At higher elevations the temperature drops lower during the night, causing the coffee trees to produce more sugars in the cherries as a protection mechanism. This increase of sugars in the cherries adds sweetness and a bright acidity. Higher elevation farms have better soil drainage, less oxygen in the air and moderate rainfall. These conditions create an environment for slower bean development and maturation, the result in the coffee cherry is more complex sugars and interesting flavour notes.
Some growing regions grade their beans based on elevation, such as SHG (Strictly High Grown) which refers to coffee grown above 1400m. High elevation coffees typically fetch a higher price per pound based on their notable flavour characteristics. It has also been noted that coffee trees will have less yield at higher altitude, factoring partially into the higher cost per pound.
Coffee grown at lower elevations is exposed to higher average temperatures and less rainfall, creating a harsher environment for the coffee trees causing them to develop more rapidly. This rapid maturation creates coffees with more simple and neutral flavours, as well as beans with low density that creates challenges for even development during roasting.
The influence of soil properties on cup quality varies depending on the region, the varietal and can even vary within a single farm. For example, some farms see higher cup quality with increased levels of phosphorous and potassium while other cases may see higher quality with increases of available nitrogen in the soil. Having the right balance of nutrients in the soil is of great importance for achieving a high quality cup of coffee.
(Source: SCAA http://www.scaa.org/Images/Pages/Resources)