When we buy coffee, we often read about flavours and roast profiles. Dark roasts, light roasts, medium roasts. Heck, a lot of places even infer that coffee strength is derived from the type of roast that has been achieved. Sure, that could imply the taste and bitterness and being “strong coffee”, but, whilst there is evidence that it’s possible to increase caffeine a little. It wouldn’t mean that it’s somehow given the beans a major super-charge during the roasting process.
Roasting is a critical step in the coffee-making process that transforms green coffee beans into the flavourful, aromatic beans that we use to make our favourite coffee drinks. Here, we’ll explore the process of roasting coffee beans, its effects on the flavour and aroma of coffee, and the different types of roasts.
Roasting requires a good bit of technology and expertise, too. So whilst we go over the broad strokes here, there’s a lot to it when it comes to doing it right.
Roasting
Roasting is the process of heating green coffee beans to a high temperature until they turn brown and develop the unique flavours and aromas associated with coffee. The roasting process involves three main stages: drying, browning, and development. In the drying stage, the moisture in the beans is removed. In the browning stage, the sugars in the beans start to caramelize, and the beans begin to turn brown. In the development stage, the beans continue to darken as the roasting process is completed, and the flavours and aromas of the coffee are developed.
The length of the roasting process, as well as the temperature and the amount of airflow, determine the characteristics of the roast. Light roasts are roasted for a shorter time at lower temperatures and have a light brown colour and a milder flavour. Medium roasts are roasted for a slightly longer time at slightly higher temperatures and have a medium brown colour and a slightly stronger flavour. Dark roasts are roasted for a longer time at higher temperatures and have a dark brown colour and a stronger, more bitter flavour.
The roasting process has a significant impact on the flavour and aroma of coffee. Light roasts tend to have a more acidic and floral taste, while dark roasts tend to have a stronger, more robust flavour with notes of chocolate and caramel. Medium roasts fall somewhere in between and offer a balanced flavour with a mild sweetness and acidity.
The process can also affect the caffeine content of coffee. Contrary to popular belief, dark roasts do not have less caffeine than light roasts. In fact, dark roasts have slightly more caffeine than light roasts. However, the taste of the coffee can affect how the caffeine is perceived. Dark roasts tend to have a more bitter taste, which can make the caffeine feel less noticeable.
In addition to the roast level, the origin and variety of the coffee beans also play a significant role in the final flavour of the coffee. Coffee beans are grown in different regions of the world, each with its unique climate, soil, and growing conditions. Different varieties of coffee beans have different flavour profiles, which can range from fruity and floral to nutty and chocolatey.
Overall
Roasting is an essential step in the coffee-making process that transforms green coffee beans into the flavourful, aromatic beans that we use to make our favourite coffee drinks. The length of the roasting process, as well as the temperature and amount of airflow, determine the characteristics of the roast. The roasting process can significantly affect the flavour and aroma of coffee, and different roast levels offer a range of taste experiences. The origin and variety of the coffee beans also play a significant role in the final flavour of the coffee.