“Learning how to roast coffee and getting the basic techniques just right will lead to the very best coffee flavours”
Developing Coffee Flavours Through Roasting- Here Are the Basics
The roasting of coffee plays an important role in the flavour of the coffee. Coffee beans are the seeds that have matured inside the coffee cherry. The cherries are processed and dried which are then referred to as coffee beans.
Before roasting takes place, the colour of the coffee beans are green, plus they smell like grass. At this stage of their development coffee beans don’t have that beautiful, distinctive aroma of coffee.
The coffee roasting process is when the beans are transformed from their green colour to their distinctive brown appearance. There are a couple of ways to roast coffee which will affect the flavour. There are commercial and home-roasting methods that are commonly applied.
The Flavour Of Your Coffee
Once roasting of coffee takes place, up to 1000 varying aromatic compounds are developed – these are the flavour of the coffee.
The Three Stages of Roasting Your Coffee
- Drying Stage of Roasting
The coffee bean must be dried before roasting begins. This usually takes between 4 to 8 minutes in a drum roaster. This is when the beans need to be watched carefully as they could easily burn. Drying of the coffee beans is an important step in roasting.
- Browning Stage of Roasting
When browning of your coffee takes place the drying stage continues and the Maillard reaction takes place. The Maillard reaction is when the sugars and amino acids are reduced resulting in numerous aromas and colours which is referred to as Melanoids. During the browning stage of roasting, the entire roasting process is slowed down for the development of the coffee flavours. The coffee pop at the end of browning which is referred to as the first crack. This is when the development stage begins in earnest.
- Development Stage of Roasting
The coffee cracks at the beginning of the development stage (this is called being exothermic). The bean builds up energy during the first two stages which then makes the coffee explode. During the development stage, the aromatic compounds begin to develop. Therefore, slowing down roasting is critical at this stage otherwise the resulting flavours could be too pronounced.
What is Roast Degree and How Does It Affect Your Coffee Flavour?
In coffee roasting one of the important factors is the roast degree. The roast degree is measured by using a colour meter or through tasting. Light roasts are usually more acidic in flavour and dark roasts bitter. Typically, fruity flavours can be found in lighter roasts and a more intense, burnt flavour in darker roasts.
What is Roast Time in Roasting?
Roast time plays a major role in the flavour of coffee – timing for each stage is important. Acidity is often preferred in certain coffee flavours but with an espresso, for example, the preferred coffee taste has low acidity. Slower roasting time results in a less acidic result.
Roasting Differs Depending on Which Equipment is Used
Different tasting coffee can be made depending on which equipment is used to roast your beans. Smaller roasters normally make use of drum roasters where the drum is heated with a flame. The result is a big roast energy and is a stable method. The roastmaster should be an expert, should know exactly how long the beans need to roast for astiming is imperative as the beans could easily burn.
Fluidised beds, on the other hand, roasts the coffee beans a lot faster without the possibility of the beans burning plus more aroma is extracted from the beans using this method.
The Difference in Roasting Beans for Filter Coffee and Espresso
Coffee used in espresso is usually dark and has a low acidic content with a full body flavour. Filter coffee roasting varies from one coffee region to the next and is typically not as dark as that used in espresso.
Coffee roasting is an art and science combined; an everlasting journey of discovery and practice.