Tag Archives: Roasting Sample

Coffee Roasting Temperature and Coffee Profiles

The roasting profile described here examines the relationship between heat, roasting-machine temperature, time, and the temperature reached by green coffee beans.

Working temperature and heat transfer

The source recommends a working roaster temperature between 140°C and 165°C. As roasting continues, heat moves from the exterior of each bean toward its interior, so bean temperature changes over time even when the machine’s set temperature remains constant.

The temperature of the coffee itself should be distinguished from the machine’s working temperature. The source proposes measuring bean temperature as the coffee exits the roaster.

Maillard reaction

The Maillard reaction occurs when amino acids and sugars react in the presence of heat. It contributes to the color, aroma, and flavor developed during roasting.

Factors affecting roasting behavior

Roaster performance depends on the heat source and how evenly heat is distributed. The response of the coffee beans depends especially on moisture and density.

1. Bean moisture: Green coffee should contain approximately 10–12% moisture, with a reasonably uniform moisture level across the batch to promote even roasting.
2. Bean density: Density reflects the bean’s physical structure and composition. Denser, well-selected beans can respond differently to heat and may support more even flavor development.

Roasting curves

A roasting curve tracks changes in coffee temperature over time. The process also includes a cooling curve, representing the rapid removal of heat after roasting to limit continued development.

What is a roasting sample?

A roasting sample is a representative quantity of coffee prepared for evaluation. The source describes samples of approximately 250–300 grams. A larger quantity—such as one kilogram or one pound—may be requested so that part can be roasted and evaluated while the remainder is retained as a reference.

Sample roasting and cupping are used to assess the quality, characteristics, and presentation of the beans. A light City-style roast is commonly chosen because it preserves many of the coffee’s subtle properties and flavors.

Longer or darker roasting can reduce some characteristics while intensifying others. Greater sugar caramelization may produce stronger caramel and chocolate notes, while perceived acidity commonly decreases.

Samples may also be roasted to customized profiles when the purpose is to match particular characteristics with cup-quality criteria or compare how a coffee performs at different roast levels.