The Agtron Scale

Every bag we sell prints an Agtron number, an instrument-measured score of how far the roast went. "Light," "medium," and "dark" mean different things at every roastery; a number means the same thing everywhere. Here's how to read ours.

The scale runs from roughly 100 down toward 0: higher numbers are lighter roasts, lower numbers are darker. The number is a measure of surface color: ground or whole-bean coffee reflects near-infrared light in direct proportion to how far roast chemistry has progressed, and an Agtron spectrophotometer reads that reflectance. It is not an opinion about the roast; it's a measurement of it.

The classification

The specialty industry's standard reference ties eight numbered color tiles to roast descriptions:

Where our roasts live

Typical target ranges for our five roast profiles; each batch's exact number is on its bag and its roast record:

How we measure

Every batch is read on aDiFluid CoffMeter A1, a near-infrared roast color meter that reads the averaged color of the whole sample to ±0.5 precision. We reportwhole-bean readings, taken after the batch has rested and cooled. Whole-bean and ground readings differ slightly (the interior of a bean is always a touch lighter than its surface), so when you compare numbers across roasters, make sure you're comparing the same preparation.

What the number can't tell you

Color says where a roast ended, not how it got there. Two batches can hit an identical Agtron by very different roads and taste distinctly different; that's why we publish development percentage alongside it, the share of the roast that happened after first crack. Together the two numbers describe a roast honestly. Either alone is only half the story.