Coffee Roasting Guide
Roasting plays a vital role in unlocking the delightful flavors of coffee. The application of heat unveils the secrets of the beans, causing chemical transformations that expose them to different amino acids. Thus, the coffee roasting process is both an art and a science.
Before delving into the world of roasting, it’s essential to familiarize yourself with some terms:
1. Batching: Refers to the approximate weight of beans roasted together in a single batch.
2. Pre-Heat Temperature: The temperature reached by your roaster before initiating the roasting process.
3. Drum: The chamber where beans come into contact with the heat.
4. Drum Speed: The rotation speed of the drum inside the roaster.
5. Bean Temperature: The heat level experienced by the beans, resulting in different color changes at different stages of roasting.
6. Flame Level: The primary heat source for the beans, contributing to distinct outcomes for each bean variety.
7. Fan Level: Beans are exposed not only to the flame but also to the heat wave generated, which imparts diverse flavors to the coffee.
Choosing the Right Roasting Level
Roasted beans can be categorized into four fundamental levels based on their color: Light, Medium, Medium-dark, and Dark. The final color of the beans directly indicates whether they meet the roaster’s desired level.
These beans have a light brown color and are roasted for a shorter duration compared to other levels. The aim is to preserve the beans’ natural aromas and flavors. Light roast beans typically reach temperatures of 170 °C – 200 °C. They are removed from the roaster when the first crack occurs.
Three variations of light roast are:
1. Light City
2. Half City
Medium roast coffees have a stronger flavor profile and a slightly oily surface, while still retaining some of the beans’ natural characteristics. Medium roasts require a longer roasting time than light roasts, resulting in reduced acidity and brightness. Beans reach temperatures of 210 °C – 220 °C.
Three variations of medium roast are:
Medium-dark roasts are characterized by a loss of most natural flavors but a development of sweeter caramelization. This roasting style is typically stopped when the second crack begins. Medium-dark roasts have a bolder and heavier profile with low acidity. Beans reach temperatures of 220 °C – 230 °C.
Two variations of medium-dark roast are:
1. Full City
Dark roast is the boldest and longest roasting style. It results in shiny black beans with a heavy oily surface and a bitter taste. Some ashy notes may also be present. Specialty coffee roasters generally avoid this level as it diminishes the natural flavors of the beans. Dark roasts tend to be sweeter due to the extended time for caramelization of sugars in the coffee beans.
Four variations of dark roast are: