What gives coffee its flavour?
Take a walk down the coffee aisle and browse the bewildering selection on offer. You might find words and phrases such as, rich, delicate, complex, single origin, natural, crema, body, acidity. Throw in descriptions like ‘notes of Blackberry’ or ‘warming notes of cedar’, and you’d be forgiven for thinking you’ve taken a wrong turn and ended up in the fine wine section.
There are over 100 species of coffee plant, however there are only two which are widely used in coffee production. These are Coffea Arabica, and Coffea Canephora (more commonly known as Robusta). With only two types of coffee bean being used, what gives each pack of coffee its distinctive taste? These are the three key factors that influence the flavour of your coffee:
Where its grown
Coffee plants are generally grown in the subtropics. This area gives the right climatic conditions such as rainfall and temperature. The biggest variable here is altitude, and this has a big impact on the taste of your coffee. To take two examples; coffee from Indonesia is generally grown at low altitudes - typically around 2500 feet - where there is more oxygen and CO2. This makes the coffee plant grow faster, meaning the yearly yield is much greater. It’s for this reason that Starbucks buys almost all of its coffee from Indonesia. This produces good, bold coffee, but it does lack complexity. Compare this to Ethiopia where coffee is sometimes grown as high a 6000 feet above sea level. At this height, the oxygen levels are much lower, meaning the coffee plant struggles to make the energy needed to grow. It’s exactly the same as if you were to try to climb a mountain. Because of the lack of oxygen you have to work much harder the closer you get to the top. To make up for the lack of oxygen the plant produces lactic acid and this imparts wonderful complex flavours into the coffee bean. Because the coffee plant grows much more slowly at these altitudes, the yield is much lower, which pushes up the price.
Extraction - washed vs natural
Coffee doesn’t grow in bean form on the plant. The bean is actually extracted from the coffee cherry which grows on the tree. They are the size of small grapes and dark pink, green or yellow in colour. Think of coffee beans as apple pips and you get the idea.
The most commonly used extraction method is called ‘washed’. Farmers will take the cherry and wash them with water to remove the skin and pulp. The beans are then allowed to dry in the sun for around a month, or - in regions where there is more rainfall - the beans are dried by large heaters. This method isolates the the coffee bean, meaning that no other factor influences the taste.
The other prominent method is called ‘natural’. Farmers will pick the coffee cherry and leave them out in the sun for 20-30 days. The bacteria on the cherry starts to ferment and the fruit breaks down giving the bean a sweet and creamy flavour which rounds out some of the bitterness.
The final stage of the process is an important one and sees the raw coffee bean change colour, from green to brown. The three terms commonly used to describe the coffee roast are light, medium and dark. Simply put, this refers to the length of time that the coffee bean has been roasted for. During the roasting process the moisture in the bean is extracted and the aroma of the bean starts to develop. A medium roast will start to bring out the fruity aromas as the sugars in the bean start to caramelise. A dark roast will start to bring out spicey and smokey aromas as the bean starts to turn a dark brown. This process is part art, part science. Stopwatches and calculations are as important as a keen eye and sence of smell.
The rest is up to you. You should try drinking your coffee black and without sugar. This will give you the true flavour, without milk or sugar to hide behind. However you choose to drink it, we hope this gives you some appreciation for the journey your beans have been on before reaching you.