Flick and Crash

The 'flick and crash' is a notorious phenomenon in coffee roasting that occurs during the final stages of the roast, typically after the first crack. The 'flick' refers to a sudden, unintended increase in the rate of rise (RoR), while the 'crash' is the subsequent, rapid decline in the bean temperature's momentum. This pattern is usually caused by poor management of heat and airflow as the beans become more porous and exothermic during the final development phase.

When a flick and crash occurs, the coffee often suffers from a lack of clarity and sweetness. The sudden spike in heat can cause the outer layers of the bean to roast too quickly, while the subsequent crash prevents the center of the bean from developing properly. This results in a cup that may taste 'baked'—a flat, dull, or papery flavor that masks the unique characteristics of the origin. It is a defect that roasters work hard to avoid through careful profile management.

To prevent this, roasters must anticipate the exothermic nature of the beans as they approach the end of the roast. By gradually reducing the heat input and managing airflow, they can keep the RoR steady and avoid the erratic behavior that leads to a flick and crash. It requires a deep understanding of the roaster's thermal dynamics and the specific behavior of the coffee being roasted.

For the consumer, avoiding the flick and crash is essential for experiencing the true potential of a specialty coffee. When a roast is executed smoothly, the flavors are vibrant, sweet, and well-defined. If you ever encounter a coffee that tastes strangely muted or papery despite being a high-quality bean, it may be the result of a flick and crash during the roasting process. It is a technical detail that highlights the importance of skill and consistency in the roastery.