What is development time of a roast?
Development time refers to the period between first crack and the end of the roast. This final stage is where much of a coffee’s flavour is shaped. While earlier chemical reactions lay the groundwork, development time determines how those flavours are expressed.The longer a coffee is left to develop, the more sugars in the coffee will darken, causing a stronger flavour of burnt sugar bitterness.
What are underdevlopment and overdevelopment?
Underdevelopment occurs when a bean has not been roasted thoroughly and could lead to a grassy tasting coffee. Overdevelopment can also cause undesirable flavours in coffee by becoming too caramelised and losing acidity and delicate florals.
What is development time ratio?
Development time ratio is the percentage of the total roast that takes place after first crack. For example, if a roast ends at 10 minutes and development lasts 2 minutes, the DTR is 20%.
Because every roaster behaves differently – with varying airflow, drum speed, and heat transfer – DTR helps roasters compare profiles more reliably than time alone. It’s especially useful when trying to replicate or tweak a roast for consistency.