What are the key factors that impact the taste of coffee?

Since those early days of the monasteries in Yemen where coffee first became popular, we have become quite particular about the taste of our coffee. Chances are if you’re reading this you already have your favourite coffee spot with a roaster you trust or even a preferred origin. 

But, why? Coffee mostly looks the same, right?

It all comes from the same tree. So why can coffee taste so incredible different depending on where you’re getting it from? So how do we choose a new coffee to try, and what does the label on the bag tell us? 

In this article we’ll put to one side discussions on the blending of origins and the roasting factors and assume we will buy a coffee with the right roast level for the brew method we’ll be using. Like anything natural, there are countless variables in coffee that influence the final product. Today we’ll focus on a few of the main influencers of flavour, which are origin, altitude, varietal and processing method.

When you’re selecting a coffee, there are two main categories; blends and single origins. A blend is where a roaster sources coffee from several origins and puts them together to create a desired flavour profile, the way coffee is blended is the secret sauce of the roasting world. Single origin as a term is both self-explanatory and deceiving. 

Let us look at our Mexican single origin for an example. It can be described as a single origin in several ways. It would be considered as a single origin by country in the sense it was sourced from Mexico. We can go a little further and say it is a single origin from the La Chiapas region. We can then narrow it down even more and say it is a single origin from the Finca Saint Teresa farm in La Chiapas region in Mexico. 

In the above example we can see that all three descriptions are accurate but the more you narrow it down the more you can narrow down what the coffee is likely to have as inherent taste properties.

Where coffee is grown also gives a few clues as to what we can expect in the cup. The reason for this is something referred to as terroir characteristics. Terroir (/ter’wa) defines the complete natural environment such as the soil, moisture, topography, and climate. Using this information, we can choose a coffee that’s from the same origin if we wish to taste something similar, or alternatively we can choose something from the other side of the world and expect a completely different coffee experience.

Coffee, in particular arabica, is quite a fickle plant and does need quite specific conditions to grow and thrive. As a result, coffee generally won’t produce high quality cherries too far away from the equator. In fact, we’ve named the area “The Coffee Belt” and it is found between the Tropics of Cancer and Capricorn. With the higher humidity and more temperate climate, these tropical regions allow for coffee trees to deliver nutrients to the fruits for a longer time. When we as roaster buy green beans, one of the pieces of information that is provided is the “maturation time”. This gives us some more clues as to the quality of the coffee because, the longer the flower takes to turn in to a ripe cherry, the more intense the flavours of the bean tend to be. 

Something else that you may find on the label of the coffee is the altitude the coffee was grown at. This is a significant factor as it influences the maturation time of the coffee. While the tropical and subtropical climates having consistently warmer temperatures throughout the year, a higher altitude brings a more temperate environment for the plants to nourish the cherries and give a clear and vibrant taste when roasted and brewed. 

Some of the best coffees in the world are grown at an altitude of between 1800 - 2200 meters above sea level (about twice the height of the Burj Khalifa, the tallest building in the world) where sometimes the only way to access these cherries is by foot, carrying the coffee back down the mountain in baskets on the backs of the pickers for hours, after having selectively only picking the cherries at exactly the right stage of ripeness, and this is done daily for months on end.  

The next part of the equation we can talk about today is the varietal of coffee tree. Coffee trees are not “open pollinated” plants, what that means is that if you were to take an Heirloom seed from Ethiopia and plant it in let us just say Brazil, you will genetically end up with a different plant or genus of the coffee tree. 
Like grapes or apples, different varieties of coffee trees will inherently have distinct characteristics. An example of this is something like a Typica, which is mostly grown in Mexico and Central America, it generally delivers a citric acidity with some floral notes and is known for its clear and clean flavours. To learn more about the different varietals check out “Coffee varietals - A Snapshot” here.      

Finally, processing method is the last part of the puzzle that influences what the green bean has to offer before being roasted and brewed. Traditionally, post-harvest coffee processing was done in one of three ways, natural (dry), washed (wet), or semi-dry. As we would expect, as the industry has evolved, we now have a vast number of variations of these processing methods, which we discuss in “A summary of Coffee Processing.”

Processing the coffee in its simplest explanation is controlled fermentation used to further enhance the profile of the green bean. The practice involves removing the flesh from the fruit and drying the seed to a moisture content of around 11-13%. Moisture content outside of these parameters could result in the green bean going “off” if too wet or, if too dry, combusting in the roasting process. Once again when choosing a coffee from its label, pay close attention to this part as the processing method will dictate the overall “feel” of the coffee and can be a significant factor in influencing the flavour of a coffee. 

Well done! You’ve made it to the end of this article!  

We hope that the above information will give you a great guide to your next bag of deliciousness. 

Happy brewing!