Data-logging software such as Cropster and Artisan have dramatically improved the level of control roasters have over their profiles they let users visualise temperature changes in the roast in real time. According to Scott, before this type of software became widely available, virtually all roasts followed a characteristic pattern in their bean-temperature rate of rise (RoR). resulting in what he refers to as the ‘unmanaged roast’.
Here’s the profile. When the cold beans are dropped into the hot roaster, the bean temperature initially rises rapidly. As the bean temperature increases throughout the roast and approaches the temperature of the roaster, the rate of rise gradually declines. Shortly before first crack, the rate of rise stops declining and may even accelerate slightly.