Diedrich IR-5 Analysis by Doris Garrido
Some things I noticed on tasting this Sumatra is that it would use a great amount of gas power after the turning point, but just for a little bit, because after the color change it would have enough energy to move through first crack on its own. It is like the moisture is saying “bring the heat,” and the density responds “calm down.”
I wanted to roast this coffee looking for citrus juiciness and modulating the sweetness in the most delicate way I could. For this, I decided to run the whole roast with air by warming the drum to a higher temperature and then making it drop with air (I did the roast analysis on a 5 kilo Diedrich with a 5.5 lb. batch) and get it stabilized before I charge the coffee.
416F was the charge temperature. I got the drum stable and charged the coffee right there, starting the gas at 70%. Applied more heat until reaching 100% after turning point and left it there just before the color change at 313F (4:50). At 373F I increased the airflow to 100% and waited for the first crack. At this point, the roast was running slow, and it was hard for me to hear the cracking, I went by eye and marked it at 376.4F. I spent 1:59 seconds on post-development and dropped the coffee at 380F. This was a 10:49-minute roast.
I believe the low temperatures I got during Maillard and post-development helped me to bring a cleaner sweetness that mixed with the vibrant acidity and were exactly what I was looking for. Flavor notes on the cupping table: Lemon grass, lemon tea, pomegranate, lemon zest, chamomile, brown sugar, herbal tea, silky mouthfeel, and long-lasting finish. After a few days of roasting, I brewed some of it for myself and I was surprised by the high-spice aroma I got, and sweetness opened up great. I will say that this coffee has a lot of flavors to play with. On this roast I wanted a clean sweetness and acidity, overall I got it, but if the goal is bringing more of the chocolate, that is also there for sure and you can have it -- I would say by keeping the heat a little longer.
