Why Rate of Rise is a bad reference point for optimizing flavour in coffee roasting

As a consultant and trainer, I’m constantly confronted with the concept of Rate of Rise as a superior reference point for improving roast profiles. With our scientific background and strong commitment to only use concepts that are explicitly helpful for coffee roasters to create successful products for customers we have to speak up about the misleading nature of how Rate of Rise often is obsessed by by students all over the world. It is the single most discussed concept that I have to handle during all my courses and dismantle in my students minds before we can get to the userful concepts that actually makes a difference in their lives and are actionable from a business strategic perspective. The content of this blogpost is the result of discussion this with hundreds and hundreds of students and clients so I think it is relevant and useful to make a separate blogpost about it even though it was also dealt with from many different angles in our podcast series about Coffee Science.  It will show you how our thoughts are not just ‘our opinion’ but deeply embedded in the scientific tradition all the way back to Plato and through the centuries of refinement and improvement of scientific thinking! Where the science podcast series was structured from the point of view of science this article is a good example of how science can be used practically on a single technical subject that has caused quite a lot of confusion. This article is a condensation of the approach I have when the subject of Rate of Rise is discussed during courses and consultancy sessions. To save time and get this subject over with before these sessions we will systematically refer students and clients to this podcast before the event. 

Links

• The blogpost Roast profile analysis that explains the concept mathematically
• A deeper dive into CoffeeMind approach to science: podcast series about Coffee Science
• The scientific article: “The Effect of Roast Development Time Modulations on the Sensory Profile ”. 
• Differential calculus
• The sensory data showing even coffee professionals struggling to taste difference between big differences can be seen in this passage in this YouTube webinar
• If you want to go through the themodynamic control excercise on your own equipment you can do it with this affordable e-learning program: Roast Profile Design Basics for only €30.
• Our Roasting defect article (behind paywall): Common roasting defects in coffee: Aroma composition, sensory characterization and consumer perception
• Go deeper in our overall competency roadmap to make startup roasters successful roasteries:  Your Perfect Coffee Roastery
• Our free research paper "The Effect of Roast Development Time Modulations on the Sensory Profile "
• If you want to improve your sensory skills check out Ida's scientifically proven approach released as an e-learning program with supplied sensory kit