What is crash and flick in coffee roasting?

Crash and flick describes a Rate of Rise (RoR) pattern at or around first crack in which the RoR drops sharply (the "crash") before rising again (the "flick"). It is one of the most discussed RoR patterns in home roasting forums and a common point of confusion and debate about what it means for cup quality.

The crash occurs when the bean mass undergoes the endothermic-to-exothermic transition at first crack while roast heat application has been wound back too aggressively beforehand - the RoR falls steeply. The flick is the subsequent exothermic burst as first crack reactions release energy, causing the RoR to rise again briefly. The resulting RoR curve looks like a sharp V shape around the first crack event.

Whether crash and flick meaningfully harms cup quality is contested. Some roasters argue that a smooth, gently declining RoR through first crack produces cleaner, more developed results. Others find that mild crash-and-flick patterns have negligible cup impact when the overall development time and end temperature are appropriate. The practical guidance most commonly given: aim for a gently declining RoR that passes through first crack without sharp crashes or spikes, treating crash and flick as a signal to refine heat management in the pre-crack window rather than as a definitive quality indicator.