Understanding develop times

Hello everyone. Been an avid lurker for some time…lol! Messing around in the roast analysis portion on “my roasts” I notice that develop time is not what I thought it to be by just watching the roast chart as it is occurring. For clarification purposes, I normally tag the beans as yellow when they no longer have any green hues left, and sometimes it is not very long before they take on the cinnamon coloring. As I understand, develop time is the time that the beans are between the yellow phase and first crack…is this not correct? I have produced awesome roasts…so I must being doing something correct…just want to narrow in on processes and the correct phase times and descriptions.

This video will help you get a good grasp on what you are seeing between yellow and 1st C and beyond which is the Maillard phase.

Roaster School - Season 2 - Episode 3: From Yellow to First Crack

Thank you PC. I have watched most of the videos from Mill City. They have awesome information. When looking at my develop time in analyzer, let’s say it shows develop time of 185 secs…I marked yellow at 6 minutes and 17 seconds and marked first crack at 11 minutes 40 second, and didn’t end until 14 minutes and 43 seconds. Where is the 185 seconds coming from???
Roast World - Cup, grade, and analyze your coffee roasts in depth (actual roast log)

(Screen shot of roast analyzer for the same roast)

They are showing the true development time at 183 seconds; the difference between start of FC and Drop. 14:43 minus 11:40 is 183 seconds. Not sure what the relevance is for the devTime. Hopefully Aillio will chime in and explain why we need both of those measurements.

That makes complete sense now…thank you Wayne! So as I understand develop time, it is not from the very onset of the yellow phase all the way thru drop, on here at least. The video suggests that it is a key point of the development, as I believed it to be. Key characteristic of the coffee is developed in the yellow phase to 1st crack, and then attenuated from 1st crack to whenever the roaster decides to drop. True dev time here is just how long the roast is from fc to drop time.

Drying time is from charge to yellow. Maillard is from yellow to FC. Dev is from FC to drop. The time needed in each of these phases depends on the bean you are roasting. A lot of people struggle with marking the dry phase/yellow point. I have learned over time that consistency is what is most important. Most of my roasts are dry at around 170-175C. I always mark dry in this range and don’t split hairs about color. Hope this all makes sense.


It makes perfect sense Wayne. Thank you for expounding on the subject. I more or less grouped the 2 phases together all into developing. I do understand that the maillard reaction time from yellow to fc is important in setting the flavor of the bean, and the time kept after fc to drop (or second crack, if you roast that far) further enhances, or augments the character of the bean set in the maillard phase. I don’t plan on changing the way I roast, or when I classify my points. I am learning. hopefully, how to better utilize auto-charting. This is my first set-up that has had a chart scrolling, and not being penned in by me manually. I am really liking it!