There are thousands of varieties of coffee around the world that come from hundreds of different beans. Each coffee has it's own unique properties and flavour but what makes up all those flavours you hear about? The hints of exotic fruits, the chocolate and nuts, the aromas and characteristics. Well as it turns out almost everything across the entire journey from seed to cup! Coffee is considered one of the most complex foods on the planet with around 1500 chemical compounds. There are so many steps along the journey that influence the final product.
Terroir is often used to describe wine, but can also describe coffee. It comes from the French word “terre”, which translates to earth or land. Terroir encompasses the land and growing conditions of a region or farm. All environmental factors such as soil, annual rainfall, temperature, elevation, latitude, sunlight or shade and even nearby flora and fauna can have an effect on the coffee’s characteristic and the final taste of the beverage.
Planting & Nutrition
Coffee seeds are usually planted in large beds in shaded nurseries but can sometimes be sewn straight into the ground. Being exposed to direct sunlight as a seedling can directly impact the bean. This impact can be so significant that it may even reduce the overall yield of the farm.
The nutrition of the developing coffee plant is also important and is dependent on things such as irrigation, pesticides and fertiliser. Even the type of fertiliser (synthetic, organic, biodynamic) and the frequency of fertilisation can influence the development of the bean.
Again this term tends to come from wine referring to the different variety of grapes but is also applicable to coffee. There are two main species of coffee “Arabica” and “Robusta” of which hundreds of varietals derive (Typica, Caturra, Bourbon, Gesha etc). Each varietal has different characteristics (flavour, aroma, body, acidity) and these characteristics can change substantially depending on the earlier mentioned terroir, planting & nutrition.
The coffee fruit or cherry as it is referred to carries the coffee bean inside. The cherries can be harvested by a mechanical machine or by hand. There are typically two methods to harvesting coffee; Strip and Selective picking. Strip picking involves all of the cherries being stripped off the branch at one time whereas Selective picking focuses only on harvesting the ripe cherries.
Harvesting ripe coffee will ensure a sweeter, cleaner & smoother taste if properly grown. A tree that has not drop its old leaves before it is harvested is ideal in producing an optimal bean.
Processing can be considered one of the biggest factors in determining flavour & aroma. There are three main techniques that are used: natural/dried-in-the-fruit, semi-wash/honey & wet/washed
Natural processing/the dry method is the original method of processing coffee and still used in many countries where water resources are limited. The freshly picked cherries are spread out on a large surface and left to dry in the sun with the skin surrounding the bean still intact. This results in a fruitier flavour & aroma often like berries and can mask or overpower other subtle attributes you might taste in a washed version of the exact same bean.
The semi-washed/honey method involves removing the flesh but leaving intact the surrounding layer of sweet mucilage while the bean dries. This tends to enhance sweetness, slightly round the acidity & provides a heavier body.
The wet method removes the pulp from the coffee cherry after harvesting so the bean is dried with only the parchment skin left. This tends to showcase acidity & terroir in the bean. Fermentation with or without water/mechanical removal is ideal for removing the pulp. The result is an experience true to the beans response to its prior circumstances.
Beans that undergo processing by the wet method must now be dried to approximately 11% moisture to prepare them for storage. Too hot and fast will leave the coffee with a woody, papery flavour. Too slow and incomplete and the coffee will taste musty/mouldy.
Coffee can last up to 14 months in storage without losing its freshness if it has been properly dried and stored in ideal conditions. The longer the bean sits in storage, the more faded the acidity, the heavier the body & the woodier/muskier its flavour becomes. It's all about what you want to experience. The age of coffee can have a dramatic impact on the final cup.
Roasting transforms green coffee into the aromatic brown beans that we purchase in our favourite cafés. When the beans internal temperature reaches about 400 degrees Fahrenheit it begins to turn brown and the caffeol (a fragrant oil locked inside the bean) begins to emerge.
Roasting can determine whether or not you taste toffee or peaches from the exact same bag of coffee. If roasted too dark all coffee will start to taste the same. Essentially the organic compounds that make up the coffee will be carbonised.
Even if everything has been done right up to this point, it can still be ruined if it is roasted poorly. Roasting is the art of presentation: enhancing the desirable features while reducing the undesirable (this includes sweetness, acidity, flavour, body, aftertaste, & intensity).
This is the final stage and there are still many factors that can influence the taste of your morning cup. The grind of the bean is first! The objective of a proper grind is to get the most flavour in a cup however the coarseness of the grind will change depending on the brewing method.
Next is the water temperature, too hot and the coffee that's travelled all that way has now been burned. The length of contact and exposure of coffee to water is equally important too long and again we’ve burned the coffee, too short and the taste will be weak and watery.
There are also different pressures (Espresso, Aeropress, Mocha pot, siphon), exposure types (Drip, Full immersion) and filtration methods and materials. Each brewing method by design, brings about certain qualities in the bean.
The beauty about coffee is the final taste can be changed by any number of factors. It can take up 3-5 years for that budding coffee seed to grow into a little red cherry. From there it travels the globe where a perfect alignment of factors deliver you that soul enriching kick.