A beautiful shot of espresso with thick crema. A steaming latte with perfect microfoam. Espresso puts your coffee under a microscope and makes the flavors much more apparent. If done right, espresso is magical. If done wrong, it’s unpalatable.
The approach you use to roast coffee that will be brewed in a true espresso machine is different than what you do for nearly all other processes. Typically, a roaster’s approach for espresso is to bring down the acidity of the roast and bring up the sweetness. Both of these elements are very impacted by your roasting approach. In simplest terms, to change these elements, you stretch out your roast in certain areas.
Like the name implies, an espresso blend is a mix of different coffees to create an espresso with certain attributes. Single origin espressos have become more popular, but espresso blends are a majority. There are two main approaches for roasting an espresso blend: pre-blending and post-blending.
In pre-blending, you combine the different beans you’d like to use at ratios you design, roast everything together, evaluate the results through cupping, and adjust to change characteristics. Ways to change characteristics include altering coffees you used, changing coffee ratios, or changing the roast strategy. If your green coffee is very different, it can be very difficult to pre-blend. For example, low elevation Sumatra which is less dense and can’t take as much heat and a high elevation Colombia which is much denser and capable of handling heat. If some of the coffees in your blend are similar, then you can pre-blend and find success. When we roast for espresso, we pre-blend similar coffees together and post-blend the remaining.
A huge part of making a successful espresso blend is post-blending and sampling coffee to get the flavor characteristics you want. For espresso sampling, espresso is unique in that it requires a longer waiting process: to have a quality test via espresso extraction, you really need to wait five days after roasting before trying to let the espresso degas.
Next time you have a really great espresso or espresso drink, imagine all the testing and blending that went in to create that perfect balance of flavors.
Photo: Roasting facility at Topeca Coffee Roasters from our roaster’s continued education roasting program.