Diedrich IR5 Analysis by Doris Garrido
Roasting a natural Sumatra doesn’t happen frequently, but it is a pleasure to encounter coffees of this region most known for wet hulled coffees. This specific coffee presented a clean, bold body with grapefruit notes and a sweet berry finish.
Key considerations for this roast were its low density and slightly high moisture content. My initial approach was to slow the beginning of the roast, adding heat on the Diedrich after the turning point until the color changed, which theoretically worked. However, since this is a natural coffee, the beans began absorbing the heat very quickly as they lost moisture. This is exactly what happened during my roast.
I chose to start the roast at 420F. From there, I applied 70% gas for about three minutes, just after the turning point, and dropped the heat shortly after the color change. This proved to be a bit too much heat. This coffee absorbs the heat very easily, and I noted that the turning point happened at 191F, which is evidence of how soft the beans are, indicating that a gentler heat application would be beneficial. Prior to first crack I opened all the air flow to manage the yellowing and smoke. The development phase concluded in a swift 1 minute and 19 seconds.
In summary, I found that this coffee absorbs the heat quickly from the beginning but we must be careful and the end of yellowing, as it can take over. My roast finished at a slightly higher temperature than I planned but did not erase the flavors. I will keep this coffee lighter on following roasts. Overall, the cup presented notes of grapefruit, almond paste, black tea, blackberry, boysenberry, caramel, a touch of cloves, lemon zest and Seville oranges. It was a sweet and bold cup of coffee with a subtle acidity and berry finish.
