Charge temperature: Is the temperature inside the roasting drum when it first starts roasting – that is, when coffee is loaded into the roasting drum.
This temperature will generate sufficient thermal momentum to finish the roasting process. Low temperatures can wreak havoc on seed development, resulting in undeveloped beans. Excessive heat may cause the seeds to burn.
There is no single one that can determine when the coffee machine should be refilled. This value is affected by the batch size, roasting, and ambient temperature. Varied roasters can produce varying results due to different heat probe setups.
Particle density is also significant when considering the intake temperature, as solid granules may require greater charging temperatures than porous granules. Coffee that has been naturally processed requires a lower initial charge temperature than coffee that has been wet-processed.
This is because processed coffees have a higher natural sugar content, which causes them to burn quickly and readily. (Perfectdailygrind cites Danilo Lodi of Dalla Corte Espresso as a recognized judge of the World Barista Championship)