Flick and Crash

The 'flick and crash' is a notorious phenomenon in coffee roasting that occurs during the final stages of the process, specifically around or after the first crack. It is a technical error that roasters work hard to avoid, as it can significantly degrade the quality of the final cup.

The 'flick' refers to an unexpected, sudden increase in the Rate of Rise (RoR) as the beans enter the development phase. This is often caused by the exothermic nature of the first crack, where the beans release energy as they expand and crack. If the roaster does not anticipate this energy release and reduce the heat, the RoR will 'flick' upward. The 'crash' follows shortly after, as the bean temperature stalls or drops because the roaster has over-compensated or the beans have exhausted their internal energy.

Why does this matter? A flick and crash cycle often leads to a 'baked' coffee. Baked coffee is characterized by a lack of vibrant acidity, a hollow body, and cereal-like or papery flavors. The coffee may taste flat and uninteresting, even if the roast color looks perfect. It is a classic example of how a roast can look correct on the surface but be fundamentally flawed in its chemical development.

In practice, avoiding the flick and crash requires precise control of airflow and heat application. Roasters use software to monitor the RoR in real-time, making micro-adjustments to gas and fan speed to keep the curve smooth. For the consumer, this means that the roaster is paying close attention to the thermodynamics of the roast, ensuring that the coffee is developed evenly without the harsh, burnt notes that come from an uncontrolled flick or the dullness that comes from a crash. It is a hallmark of a roaster who prioritizes precision and consistency.