Coffee Roasting Finale #7 - Further Notes and Recap

Further Notes & Recap

            Cupping your roasts, tasting your coffee, is important. You can probably tell whether a coffee tastes good, tastes like cardboard, etc, even if you are not a savant able to taste the difference between mango acidity and apple acidity. Traditional cupping of roasts is a great way to test multiple different roasts at the same time. Because the grounds sit in the coffee, it also promotes all the possible notes and flavors you might find. This makes it especially helpful for those that travel to farms trying different beans. However, for this same reason, it can mask some mistakes, especially if you roast light. Cupping can sometimes mask underdeveloped coffee, so it is important to later try your coffee in a traditional way (pour over, espresso, etc). If you are just starting out, and only have 2-3 beans to try, I recommend just doing a pour-over. Practice cupping on the side to practice tasting and articulating lots of different notes from the flavor wheel. Coffee will generally taste best after 7 days or so, and light coffee can sometimes go from tasting green to well-developed in that time. For espresso, it is best to wait 1-2 weeks after roasting.


            Coffee can degas for 24 hours after roasting, in a dark air-conditioned room, before being placed in airtight containers for further resting and storage.


             Automation might not be as capable as a very good roaster, but it is often more capable than a beginner or intermediate roaster. From automation methods, we can also gather some hints at what the most effective aspects of roasting are. What I see when using automation is that the most consistent tasting coffee occurs when the automation follows the Bean Temperature curve exactly, matching Turning Point and the times for DRY, MAI, and DEV. This tells me that some anomalies in ROR might be acceptable for a beginner or intermediate roaster, provided they charge correctly, carry the coffee thru each phase in an appropriate amount of time, and generally follow a declining ROR from Peak ROR to Drop. Charging temperature, consistent Turning Point, and the time spent in each phase are probably the most significant factors determining flavor of coffee.


              If you want to know what beans to start with, I recommend beans that are forgiving and have flavor profiles similar to what you know. Forgiving beans that I know of include Colombia, Kenya, and Costa Rica. Guatemala and Brazil are also good options.


                Regarding bean density: beans that require more heat generally include: higher altitude beans, larger beans, washed process beans. This will include Guatemala, Colombia, Kenya, Ethiopia, and more. Beans that require less heat: smaller beans, lower elevation beans, and naturally processed beans. This will include North & Central Mexico, Brazil, and Hawaii. Many beans fall somewhere in the middle, such as Costa Rica and Sumatra. Besides this, less dense beans will include decaf beans, older beans, and any beans exposed to light and air during storage.


                Less dense beans can also benefit from slightly longer DRY times than denser beans. Naturally processed beans are more uneven in their density, and the longer DRY time helps dry & heat them evenly. A slightly increased airflow can also help even heating.


                Washed beans generally have higher acidity than naturally processed beans. Natural beans are better at revealing origin flavor notes.


                Drum speed: research your roaster manufacturer and what other people with your roaster use as a drum speed setting. I generally recommend that drum speed be the fastest you can go without defects or losing beans. If your beans get sucked or thrown out into the exhaust, your speed is too fast. If you get scorching and some of your beans are black while others are well-roasted, the beans are either sitting on the drum too long at a time (too slow spinning) or they are sticking to the drum walls (too fast spinning).


                 On temperature readings: when it comes to bean probe temperature readings, every machine, probe, and placement will be slightly different. Get a feel for when you commonly achieve Turning Point, Dry End, First Crack, and Second Crack. Keep these differences in mind when reading other roasters data and recommendations.


                Remember that an increase in airflow while you are still applying significant heat (e.g. 50% or more of your max for the roast) will likely result in an increased ROR. Increased airflow while using medium heat can slow decline of ROR.


                Momentum is not equal to ROR. If you notice you are tasting green coffee, and you know you need more momentum, the answer is not to increase the ROR where you enter First Crack. You must use more heat earlier in the roast to increase momentum.


                Finally, to try to collapse everything into a few useful sentences: The most important factor in roasting is inner bean development and momentum. The next most important factor is DEV: how dark and how long your DEV time is, in relation to the overall time. The next most important factor is the Peak ROR and the ROR curve. Next most important factors are charge temp, turning point, DRY time, and MAI time.


               With some hesitation, I recommend that in your roasting you find the fastest potential roast time that you can get in your coffee (without defect), and then lengthen it a bit, to taste. If you can achieve a well-developed fast roast without roast defects, you can slow it down to adjust and deepen flavors. To me, this is a faster way of learning than constantly butting up against bad coffee and wondering what factor among many you ought to adjust.


                I hope this blog series has served to provide you with a shortcut to good roasting, and puts what other experts and teachers say into a useful and corrective context.