What are Roast Curves?
Roast curves are the graphical representations of temperature changes during the coffee roasting process, typically plotted as bean temperature over time. Roasters use these curves to control flavour development, consistency, and repeatability in specialty coffee roasting.
Why roast curves matter for flavor development
Roast curves are central to shaping a coffee’s flavor, influencing acidity, sweetness, body, and overall balance. They allow roasters to consistently replicate successful results across batches, while also providing a transparent record for learning and refining technique.
Beyond consistency, roast curves are tailored to the intended brewing method and local variables, like water composition and temperature, which can significantly affect extraction. This means that the same coffee might be roasted differently in Denmark versus Norway to achieve a similar cup profile, highlighting the interplay between roast, environment, and final sensory experience.
Specialty vs. Commercial Coffee and Roast Curves
In specialty coffee, roast curves are meticulously designed and monitored to highlight the unique characteristics of each lot. Roasters often use advanced software, detailed logging, and repeated trial runs to fine-tune profiles, balancing development time, temperature changes, and airflow to maximize sweetness, clarity, and complexity.
In commercial roasting, by contrast, the emphasis is typically on throughput, consistency across large volumes, and operational efficiency, which can result in less nuanced roast profiles and a reduced ability to express the distinct qualities of individual coffees.
Where Nordic Approach fits in
Our production team tries to standarize curves/profiles to efficiently bring out the potential and flavor of our coffees through cupping. Costumed, as much as we can, to roasters expectations on roast profiles.
FAQ about Roast Curves
Q1: What’s the difference between bean temperature and environmental temperature in a curve?
A1: Bean temperature tracks the coffee itself, while environmental temperature measures the heat inside the roaster chamber. Both are important.
Q2: Do all roasters need to track curves?
A2: For specialty coffee, yes they should, consistent roast curves are essential for quality control.
Q3: How do roast curves affect flavour?
A3: Yes, generally: a faster roast can preserve bright acidity and floral notes, while a slower roast often develops more sweetness, body, and caramelized flavors. However, the effect also depends on bean origin, density, and how the development phase is managed.