That’s right altitude. Have you ever wondered why some coffee labels tell you how high above sea level your coffee was grown? Well the reason for this can be explained using the diagram above. The majority of coffee farms lie well above sea level, on rain-soaked plains. There’s a natural reason for this and it also explains why altitude has a major impact of the flavour of your coffee.
Being a fruit, coffee plants are susceptible to attack from pests who are after their ripe and juicy cherries - not to mention some unpleasant micro-organisms too. So mother nature gave the coffee plants a natural insect repellent in the form of caffeine. Caffeine is an alkaloid, which on its own or in large doses is very bitter and quite unpleasant to taste.
Robusta coffee plants are loaded with caffeine, which allows them to survive at much lower altitudes (sub 1000masl). This is great for farming but not necessarily for flavour on its own. That’s why robusta coffee is commonly used for rich espresso blends, as it’s designed to give them a much ‘stronger’ flavour - side note, when we refer to ‘strength’ in coffee flavour, what we’re usually referring to is its bitterness. Believe it or not, some of the lightest tasting filter brews can contain just as much, if not more caffeine than the harshest tasting espressos.
Don’t be fooled into thinking that robusta coffee is a minor footnote to the industry however, roughly 30% of the world’s coffee produced is from robusta plants. It is most commonly grown in Vietnam, Indonesia and India, although these countries do also produce arabica coffee in smaller amounts as well.
Most arabica coffee plants are cultivated around 1500m above sea level, but plantations have been as high as 2800m. Why? Arabica has a much lower natural caffeine content than robusta, so needs the advantage of growing at altitudes where less pests and threats to their cherries are less likely to survive.
At these altitudes the weather can play an even more important role too in developing the flavour of the coffee produced. On mountains and huge hills, valleys and secluded vistas in rain-forests have been carved (either by man or nature) to create the perfect micro-climates for growing coffee. Here the temperature, air moisture and rainfall can combine to create just the right conditions, consistently year on year.
This, combined with the lower caffeine content explains why it is easier to identify more sweetness and subtle floral notes in arabica coffees. Over time it has also become much easier to attribute specific flavour notes to the region where the arabica coffee was grown, just like wine.
It is these unique micro-climates that have consistently produced the world’s best coffees and even played a part in defining the criteria for ‘Speciality Coffee’. Once you get past the back-breaking effort of farming at these altitudes, they really are a picture of paradise!
We now know the the key ingredients for growing Speciality Coffee and we can point on a map to where most of these conditions come naturally. For the next article in this series we’ll take a closer look at some of the origins most famous for producing incredible coffee.