Last week we talked about roasting curves and the importance of holding a steadily decreasing Rate of Rise as your roast progresses. We alluded to a few key inflection points that we’re going to dissect further this week: the Rise, Crash, and Flick.
Rise, Crash, Flick. These terms are relatively self-explanatory when looking at the roasting curve above, but refer to the seemingly natural behavior of your RoR before, during and after first crack. Mismanaged roasts will often show a rate of rise that bumps up slightly before first crack, plummets during first crack, and then shoots back up sharply towards the end of first crack. The crash can bake your coffee and the flick can char your coffee, upsetting the delicate flavors you were hoping to highlight.
We believe it’s super helpful to understand what’s going on with your coffee during these critical transitions so you’re motivated to manage your roasts. Conceptual understanding also helps those who don’t have access to computer readouts manage their roasts intuitively.
Rise. As coffee approaches first crack, the moisture in the coffee is heating up radically, but with little opportunity to escape. The bean temperature starts to creep upward, as seen on the chart. If you’re not watching a chart, you will notice the beans start to emit an increasing amount of smoke/steam as they swell up. Experienced roasters recognize this as the coffee approaching first crack.
Crash. When the beans start to crack, they begin an exothermic release of heat, energy and moisture. As that hot moisture/mass suddenly leaves the beans, the bean temperature falls rapidly. This blast of moisture, now entering the roasting chamber, briefly cools the beans. This usually illustrates itself on a roasting curve with a sharp RoR crash.
Flick. Once the moisture escapes and vents out of the roast chamber, the beans have a tendency to quickly heat up again, and the RoR will rebound. Thus, the “flick”. This typically happens around 2 minutes after first crack.
The Problems. We can recognize these three problems as something other than the desired gentle, steady development of your coffee. If the bean temperature crashes suddenly, the roast is essentially stalling (baking) and you can expect to leave nuance and sweetness on the table. When bean temperature flicks, you can expect to char the beans while they are in a very delicate state. It’s worth noting that neither of these traits will necessarily be visible, but a trained palate will be able to taste them.
How to Avoid the Rise, Crash, and Flick. These three traits usually go hand-in-hand, so managing them is really about a steady decrease in heat application to maintain a gradually declining RoR and gentle development.
Our biggest tip is avoid overworking the heat temperature and throttling it back and forth to “compensate” for these fluctuations. Doing so seems like a natural response, but it really only masks what’s going on in the beans. Some roasters may suggest counteracting the crash by increasing the heat. This is not recommended. We’re not certain, but science might suggest that adding heat into a moist environment can lead to scorching or charring.
Be attentive during the whole roast cycle, not just at these three inflection points.
Additionally, doing multiple roasts of the same bean will give you an idea of what temperature catalyzes first crack and how early it crashes. No surprise here, but not all beans roast the same. If you can accurately predict when first crack happens, your roasts will become infinitely better. Really.
- Some roasters incorrectly refer to the rise before the crash as the flick. This isn’t the correct nomenclature. Usually, roasting curves that show a rise and a crash, but no flick, do so because of a shortened DTR. The beans simply didn’t have a chance to get to the flick because the roast was terminated.
- Scott Rao, the RoR pioneer we mentioned last week, notes that many roasters have become so accustomed to the rise, crash, and flick that they don’t even know they are undesirable or avoidable.
- The rise, crash, and flick can easily repeat as the beans enter, sustain and exit second crack as well. But, that second flick might be the one that erupts into flames and “flicks” your nice roaster into the garbage can.