Know your types of coffee roast

Prior to roasting, the bean needs to be extracted from within the many layers of a coffee cherry. For coffee, we are only looking to extract and use the beans found in the centre (generally there are two coffee beans). The coffee cherry is made up approximately six layers; the outer skin, the pulp, mucilage, parchment, silver-skin and the all-important beans in the centre.

Before the coffee beans are roasted, they must go through a special preparation stage, which can be done through either a washed or a natural process. Dry/Natural Coffee Process Dry process, also known as unwashed or natural coffee, is the oldest method of processing coffee. After harvest, the entire cherry is cleaned and placed in the sun to dry on tables or in thin layers on patios. The natural/dry process refers to when the bean is dried in the cherry before de-pulping. De-pulping is the process of separating the coffee seeds from the outer layer of flesh. After coffee cherries are picked, they must be de-pulped within 24 hours. If the cherries pass the 24-hour mark without being de-pulped, they may produce an overly fruity, rotten flavour that can ruin the quality of the coffee. Wet/Washed Coffee Process The washed process is where the beans are dried without the cherry, de-pulped and then they are usually fermented to help in separating the rest of the pectin from the bean and parchment, then finally, the beans will be washed and cleaned before drying. In the wet process, the fruit covering the seeds/beans is removed before they are dried. Coffee processed by the wet method is called wet processed or washed coffee. The wet method requires the use of specific equipment and substantial quantities of water.

Interestingly, coffee beans are originally green with a grassy smell! The rich, brown colour, wonderful flavours and aroma we all enjoy are in fact due to the careful roasting process they undergo after harvesting. Once the beans are put inside the drum of the coffee roaster and they begin to heat up, the process causes a chemical change in the beans as they’re brought to a high temperature very quickly. Then, once they reach the ideal temperature for that particular roast, they get cooled rapidly in order to stop them being roasted further. The process may sound relatively simple, but it requires a keen eye to ensure they’re roasted to the correct standards. Find out more about the coffee roasting process in our guide.

As the name suggests, medium roast coffee is medium brown in colour, dry and generally more balanced in flavour. This type of coffee roast is roasted to a temperature of between 210°C - 220°C and is preferred by many as the flavour, aroma and acidity all entwine in a harmonious blend and often, a slightly sweeter taste and stronger aroma can be expected too. 

The boldest roasting profile available, dark roast coffee is roasted to a temperature of between 240°c - 250°c. This type is black in colour with an oily surface and a very bitter taste. The flavours are very pronounced with strong notes and often, hints of caramel can be found in these types of coffee roast.  Medium-dark and dark roasted coffee beans go through what is known as ‘second crack’, relating to an occurrence during the roasting process. ‘First crack’ is when the coffee beans will audibly pop like popcorn or puff up slightly, whereas ‘second crack’ is a slightly softer sound. It means that if the roasting process continues long enough, coffee beans will go through a second crack, which is usually caused by the oils beginning to migrate from inside of the bean to the outside.