Roasting
Development Time
The duration between the start of first crack and the end of the roast, often expressed as a percentage of total roast time (development time ratio, DTR). Development time controls the balance between origin brightness and roast-derived sweetness.
En détail
A DTR of 20-25% is common for specialty filter roasts, while espresso profiles may push to 25-30% for more solubility and body. Too short a development time produces under-developed, grassy, or sour coffee even if the bean color appears correct. Excessive development time bakes out volatile aromatics and flattens acidity. Tracking development time provides a more meaningful metric than final temperature alone for evaluating roast completeness.