Coffee roasting is tricky, but it’s not rocket science. At first, you’d think all you need to do is put green coffee into the machine, crank up the heat, and turn them brown. Unfortunately, that couldn’t be farther from the truth when it comes to roasting coffee. Coffee processing methods, including washed, natural, or honey processes, and density and moisture, will impact your roast profile.
What Is A Coffee Roasting Profile?
Unlike a piece of chicken in your oven, coffee roasting is dependent on the end temperature and how you got there. Cropster is the software we use on a daily basis. Cropster takes the data from the temperature probe (thermocouple) inside the roaster and turns that into points on a graph. Every few seconds, it plots the time and temperature of your roast, and you can mark burner and air setting changes along that graph to follow on future roasts.
Why Does Each Coffee Need To Be Profiled?
The roasting profile, or graph of the temperature over time, is what professional roasters use to develop a roast for a particular coffee and then follow it for consistency each week. For instance, let us say you are roasting a washed Ethiopian with dried apricot and oolong tea notes. To coax out those flavors, you need to roast this coffee along a specific time and temperature graph. Once you’ve done the R&D profile on it, you realize that one profile works better than another. That then becomes your roast profile for the Ethiopian, and you can use it to recreate that taste after that.
At Path Coffee Roasters, coffee roasting is both an art and a science. Our evaluations and choices related to flavor development make up the art. The science is how to achieve it. Obtaining a steadily declining ROR (Rate of Rise) is integral in producing fully developed, flavorful, and sweet coffee. Scott Rao, a well known and respected coffee roasting and brewing consultant, noticed that over thousands of roasts and many tastings, the best coffees were always ones where the ROR fell on a steady decline and avoided what he termed the “crash” & “flick.”
The image above shows a roast where there is an obvious flick and crash. The crash produces a baked coffee or one devoid of profound richness and structure, and the flick can impart roast flavors that we’re looking to avoid. While the bean temperature creeps upward, the ROR curve should hit a high point early on, and then steadily decline till you finish your roast. Currently, we roast 20 to 40-pounds at a time, depending on the coffee. Using uniform batch sizes allows us to be more consistent as we sometimes roast the same coffee over many months.
How Do We Roast Our Coffee?
Sugar browning is a crucial element to our style of roasting. We aim to source and provide sweet-tasting coffees. Roasting is how we coax out all those intrinsic natural flavors.
Our roast days begin by weighing out green first thing in the morning to cover our current orders. We like to roast our darkest coffees first so that we achieve a thermally stable roaster. We need to make sure that our roaster is hot enough so that any coffee we put in doesn’t affect the thermal stability. The roaster warms up for 45 minutes, then we cool it down to 50 degrees below our charge temperature (the temperature we choose to start our roast). Once the coffee enters the roaster, the thermocouple now immediately descends hundreds of degrees to around 180 F. At that time, our coffee and thermocouple begin to equalize, and the temperature begins to rise. Gas is applied at this time to start driving the roast, and as the roast progresses, we being to pull back on our gas to develop our roast profile.
Each coffee requires a slightly different profile to maximize its natural flavors. This profile might dictate a charge temperature adjustment because our batch size is 20 vs. 40-pounds. We might use more gas upfront than at other times and so on. Regardless, our goal is to produce a coffee full of flavor, mouth-filling, balanced, and easy to extract when brewing at home, in the office, or at your cafe or restaurant.
Toward each roast’s end, we start using the tryer to evaluate the coffee’s smell and shade. Once we’re happy, we discharge the roasted coffee into the cooling cart, cooling down over the next few minutes. It’s essential to get the coffee cool as quickly as possible to stop the roasting process that’s still taking place inside the bean. Just like a piece of meat will continue cooking once you remove it from the oven.
Coffee Roasting Conclusion
There is no such thing as perfectly roasted coffee. And no coffee roaster has a monopoly on how to roast the “right” way—roasting coffee, while a science in some ways, is also very much about personal taste. The Ethiopian coffee I roast will be roasted by another much differently because of their equipment, environment, water (will affect the cupping and evaluation of a roast), and the flavor they want to achieve for their customers. At Path, we might want to have a more balanced and fruit-forward flavor, whereas another roaster will take the same coffee and make it darker and longer to bring out more of those dark chocolate notes with reduced acidity. It’s all personal, and there is no right way. In the end, we do our best to express the exquisite flavors each coffee has to offer and do it consistently from week to week.
Path Coffee Roasters is located in Port Chester, NY, where we roast and package all our coffees weekly for our wholesale, retail, and dropshipping customers.
Please reach out to us if you have any questions. We’re here to help.