How to Read a Roast Curve Like a Roaster Does

Every roast we run gets logged the same way: temperature against time, charted from the moment the green beans hit the drum to the moment they drop. It looks technical, and it is, but you don't need an engineering degree to read the parts that matter.

The first thing to look at is the shape right after charge. Beans go in cold and the temperature dips before it starts climbing again — that dip is called the turning point, and how quickly the curve recovers from it tells you a lot about how the rest of the roast will behave. A slow recovery usually means a longer, gentler roast ahead.

The moment that actually matters most to flavor is marked on our charts as First Crack — the point where the beans physically crack open as built-up steam escapes. Everything before that point develops sugars and acids. Everything after it starts trading brightness for body. Where we drop the beans relative to First Crack is the single biggest decision in the whole roast.

We chart development time as a percentage — the time spent between First Crack and drop, divided by total roast time. A lighter percentage, like the 13% on our Guji lot, keeps more of the origin's natural fruit character. A longer development time trades some of that brightness for sweetness and body.

None of this is set by a machine preset. Our roaster reads the curve in real time and makes the drop call by hand, lot by lot, because a Guji natural and a Coorg washed bean simply don't want the same curve. That's the whole reason we log every batch instead of running one fixed profile.