Altitude & Temperature - An Intimate Relationship
When purchasing a bag of coffee, you may have realised that it gives you the altitude at which the coffee was grown. Why do roasters give this information, what are they trying to tell you from this and does it matter?
What happens when we travel up a mountain is as we get nearer to the peak the temperature starts to get colder, extremely cold at the top. We wouldn't want to grow coffee at the top of a mountain especially if the temperature went under freezing point, as the plant would freeze. If you were to flip that and have coffee grown closer to sea level the temperatures would be too high, leading the plant to mature too quickly.
It's good to remember that the longer the maturation process, how long it develops for, the more complex sugars we will get from the coffee cherry.
By having the plant come under certain stresses in development it will help it to produce more sugar in response to this but there is a balance to that. Too high a stress from heat and the plant will defend itself by shutting down their photosynthesis, the process for creating food for it to stay alive. It truly is a balancing act with growing coffee.
At a certain altitude, we find temperatures of around 18C - 23C which are ideal for growing the Arabica species. Consistent temperatures over both day and night are key to growing delicious coffee. What we achieve from this is higher acidity and a more dense cherry. Then it’s down to the roaster to decide what they want to achieve from it. As well as 500 other variables.
Altitude and temperature are mutually dependent on one another and change based on the country the coffee is being grown. It is important that we are given this information as well as the average temperature of the plant to fully understand what we might experience from the coffee we buy.
This is a huge subject and it just touches briefly on it, if you want more detail I'd highly recommend reading Coffee Atlas of Ethiopia if you wish to learn more.
Have you found differences in the flavour of your coffee grown at higher altitudes?
What’s your favourite coffee origin?
Thanks for reading 🌱