If you’ve ever had the chance to see a bag of roasted specialty coffee, you mustn’t have missed all the information included on the label. You can read about the country of origin, a specific region, farm, cooperative, or even a farmer’s name for some countries. But why would one need to know the altitude at which the coffee was grown? What can you learn from this piece of information?
The final taste of your cup of coffee is determined by many factors. It’s in now way only the end processing, such as roast style, milling size, barista’s skills and so on. There are other key factors, such as species
of the coffee tree, the soil in which it grows, and of course, the altitude at which the trees have been planted. Many people like to say, “the higher the better”. That’s an oversimplification, though. Coffee trees have very fine requirements for their growth when it comes to humidity, temperature and nutrients. The higher they grow, the longer their lifecycle is. The coffee cherries ripen for a longer period, which allows more sugars from the pulp
to penetrate the coffee beans.. Taste-wise
, the beans end up being more complex with a higher acidity. The fruity tones in the taste also shift to florals with altitude. On the other hand, caring for coffee trees in such conditions is much more difficult. Not only do they have to combat harsh winds and lower temperatures, but are also more prone to diseases caused my molds and parasitic fungi. That’s caused by the higher atmospheric humidity and also the reduced effectiveness of pesticides. The harder conditions also mean there is usually only one harvest per year, which further reduces the yields. These are the costs for a more intense taste in the final cup.
To make things more complicated, altitude is not as simple as that. One must also consider the specific geography of the country
of origin. “The higher the better” is only roughly applicable to equatorial areas. Further from the equator, the ideal altitude decreases, in order to reach the ideal temperatures for growing coffee. You no longer need 3000 m.a.s.l. to give the coffee tree a chance to realize its full potential. The ideal range of temperatures for a coffee tree to grow well is 17 – 24°C, anything more or less starts being a burden. One might consider replacing the information about altitude with average temperature instead. Unfortunately, this value keeps changing not only in the short term, but also over longer period thanks to climate change.
There is one more variable that’s affected by altitude, and that is bean density. This is of special importance to roasters. It is actually one of the most important ones. The rule of thumb is “higher density and heavier bean, better quality”. Coffee beans that ripen in lower altitude and higher temperatures tends to mature too fast and produce many tiny air capsules inside the bean, which make the process of roasting more difficult. For higher-altitude beans, this phenomenon is much less pronounced, which makes roasting not only faster, but most importantly, more uniform, which is key.
To sum things up, altitude is indeed an important factor, but must as always be taken in context of the other geographical variables. This has an unexpected side-effect - by drinking coffee, you can not only enjoy the taste and improve your health, but also expand your cultural and geographical knowledge.