A (rather) short explanation of the cupping process with Hans-Erik from Steampunk coffee. The cupping process is a vital part of getting the most out of a given bean's potential and assuring consistant roasts, as well as being a romantic ritual.
Hans-Erik takes core samples during the roasting process at each degree change from around 190-200 degrees. He then grounds and brews these samples from the lightest (lowest) to darkest (highest). Somewhere within this range is the perfect level of roasting, so the process allows Hans-Erik to refine his roasting profile and narrow his target temperature.
Because coffee beans vary so much in size (from the tiny Doi Chaang bean of Thailand to the large Monsoon Malabar of India), their roasting times and temperatures can vary significantly. The cupping process allows the roaster to ensure each bean variety has been roasted properly according to it's specific properties. Because Steampunk (and other exceptional coffee roasters) obtain their beans through direct trade, the varieties of beans and the beans themselves change from season to season. As a result, the roasting process is constantly being adjusted and fine-tuned.
While the process is time intensive and demands a dedicated attention to detail, the results can be tasted in the final cup. A fine roast achieves the perfect balance between dark and light. Not to sour, not too earthy. I credit and am thankful for people like Hans-Erik who dedicate themselves so passionately to the pursuit of constant revision and refinement.