What is the yellow point in coffee roasting?

The yellow point - also called the yellow stage or dry end - is the moment during roasting when green coffee beans transition from their initial green colour to a uniform pale yellow. It marks the end of the drying phase and the beginning of the browning reactions that define the rest of the roast.

The yellow point typically occurs when internal bean temperature reaches around 150-160°C, though the exact temperature varies by bean density, moisture content, and roasting machine. Visually it's a clear marker: the grassy, greenish colour of the raw bean gives way to a pale straw or yellow hue, and the dry, papery smell of the drying phase shifts towards something sweeter and more bread-like.

For home roasters, the yellow point is a useful calibration reference. Logging the time at which beans turn yellow relative to the start of the roast gives you a repeatable data point that helps you track whether a new batch is following the same trajectory as previous roasts. If beans are yellowing significantly earlier or later than usual, it's a signal that charge temperature, batch size, or ambient conditions have shifted. Roasters who pay attention to the yellow point develop a more intuitive feel for how a roast is progressing before first crack arrives.