Learn - Articles   -   Roastery   -   Quality Control / Cupping   -   Roast   -   Coffee Lab   -   Blog posts

The Flick updated for 2021

Perhaps the most difficult aspect of roasting is controlling the bean-temperature Rate Of Rise just before and during first crack. Scott Rao - coffee consultant, trainer and author of the book "The Coffee Roaster's Companion" - shares his insights why to watch out for "the flick" and how to prevent it.

null

blue curves = bean temperature and bean-temperature ROR

The majority of my clients ROR curves have looked like this before I began working with them. Such curves are so common that I've begun thinking of them as “unmanaged” or “natural” curves. 

Compared to similar roasts with smoothly declining RORs, such unmanaged roasts will offer less delicacy and sweetness, and may taste baked. They will often have a hint of char, even at a light roast color. 

The flick at the end of the roast causes the charred flavor and loss of delicacy. The flick indicates an acceleration in the bean ROR. Several factors may contribute to a flick, including a crash in the ROR early in first crack, reduction in the release of moisture toward the end of first crack, and overheating of the roasting environment. The most damaging potential cause is an increase in the roasting drum’s surface temperature, if for instance, the operator increases the gas during first crack in a classic-drum roaster. Like the searing of a steak, the hot drum surface will darken only the outermost layers of the beans, contributing to an uneven roast. The beans may not look burnt, but a roast with a flick will usually taste more roasted and less delicate than a similar roast without a flick. 

I have measured the color distribution of several ground-coffee samples from similar roasts that differed primarily in whether they flicked at the end. The flicked roasts usually produced a greater volume of grounds at the darkest color, with little other difference in the color distributions.

Please do not underestimate the damage imparted by a flick. Many roasters who seem to think the flick is benign have posted flicked ROR curves online, claiming that the curves followed my system (i.e., had a constantly declining ROR), but, of course, a flick indicates a rising ROR and a violation of the system. I often wonder if some roasters have been flicking for so long that they think it’s inevitable.

The flick may also mislead roasters in their understanding of how development time ratio (DTR) affects coffee flavor. Many roasters have told me that higher DTRs (i.e. 20% - 25%) produce roasty flavors (relative to bean color). But there is, in fact, a modest correlation between DTR and roastiness; every time one of those roasters showed me their ROR curves from the high-DTR roasts, their RORs contained flicks. The flicks, I believe, not the high DTRs, were the causes of the roasted flavors. All of the roasters who were open-minded enough to accept a range of DTRs while learning to smooth their RORs eventually found the roasted notes disappeared and their coffee was sweeter than it had been before.

In a typical 10-14 minute drum roast, the flick usually occurs between 16%--17% DTR (when first crack is marked using my “ETROR trick.”) Those who drop batches early in first crack rarely have to contend with flicking. However, when roasting darker, one must manage the flick and, if roasting dark enough, a likely crash after the flick.

Cropster offers several features one can use to monitor and avoid flicking the most recent one being AI based Flick prediction. Here are some additional ways roasters can avoid a Flick:

Users should use the fastest setting that their probe allows. Begin with the sensitive setting and increase it if needed. You can read more about Cropster’s three rate-of-rise settings here. One can, of course, instead view the real-time ROR number on the far right of the screen, but I find it helps to also have the curves’ values closer to the real-time readings.

I recommend roasters ensure their bean probes do not have too much thermometric lag. Typically, smaller-diameter probes read more quickly, with less lag. I recommend against using ungrounded thermocouples with diameters larger than 3mm. 

Roasters should monitor the environmental-temperature ROR (ET ROR) curve as well. When the ET ROR begins to climb too high, too fast, it may be an early-warning signal that the bean ROR is about to rise, or at least slow its descent. An exception to this is just after first crack begins.

null

Scott Rao is a coffee consultant and author most recently of the book Coffee Roasting: Best Practices. You can follow Scott on Instagram @whereisscottrao for frequent roasting and brewing tips and discussion. 

새 소식 더 보기

Roastery   -   Blog posts

Kaffee Panel 연재 - 2부: Carsten Wolters

Roestbar의 Carsten Wolters는 세척한 과테말라 핀카 비스카야 커피를 로스팅합니다. Kaffee Panel 연재의 두 번째 글에서는 독일 뮌스터에 있는 Roestbar의 Carsten Wolters를 소개합니다.

더 읽기
Cafe   -   Blog posts

순조로운 다이얼링

다이얼링이란 맛있는 에스프레소를 만들고, 품질 표준을 충족하며, 고객이 더 많이 찾도록 하는 데 있어 제일 중요한 작업입니다. 최고의 커피를 얻을 수 있도록 장비로 브루 매개변수를 완벽하게 조정하는 것 외에는 아무것도 필요하지 않습니다. 말처럼 쉽지 않다는 것은 알고 있습니다. 또한 여러분을 비롯하여 여러분과 함께 일하는 사람들을 위해 이 작업을 더…

더 읽기
Roastery   -   Quality Control / Cupping   -   Blog posts

Kaffee Panel 연재 - 1부: Philip Weller

연초에 우리는 4명의 숙련된 로스터를 웨비나에 초대하여 그들이 Kaffee Panel 대회에서 어떻게 최고의 자리를 차지했는지에 대해 알아보았습니다. 이를 위해 로스팅 프로파일을 분석하고 그들이 사용한 고유한 방법에 대한 의견을 나누었습니다.

더 읽기

뉴스레터를 구독해보세요.

다음의 업계 종사자를 의한 솔루션에 대한 더 자세한 내용을 확인해보세요.

Here should be a form, apparently your browser blocks our forms.

Do you use an adblocker? If so, please try turning it off and reload this page.