CarefreeBuzzBuzz wrote:Which raises the question for repeating a roast: Is coming closer on the phase times more critical than matching the btROR curve..
Matching the phase milestones affects the flavor profile, steadily declining ROR relates to roast defects.
I have a very hard time discerning even large changes in phase milestones. For example, I did a 500g roast of Panama Elida on my Cormorant. I didn't preheat enough and, using all the gas I had, wound up with a 12:30 roast. My normal roast on the big roaster is 8:00. The Cormorant roast didn't hit dry until over 7:00. But the RoR was steady and declining all the way. The roast tasted wonderful. Even at this extreme difference, it tasted like Panama Elida. The acidity was rounder, the body was syrupier and the cup was creamier over all, but it was yummy. Most of my customers, unless they were A/Bing both coffees at the same time, would likely not notice the difference.
OTOH, I have had experiences wear I got distracted during a roast and let the end of the roast flick because I didn't turn off the gas in time. Even though those roasts hit the same milestones, although a bit hotter at drop, it was noticeably roastier in the cup and a bit dry.
I live for the day when I have the time to sit around and try dozens roast profiles to find that magic sweet spot where I get the perfect tangerine/bergamot note. But the reality is, by the time I figure that out, the coffee would have aged more and it might not be available any more. I settle for 0 roasts defects and tried and true profiles based on density, moisture, variety and terroir.