Willie Yi-Luoma of Portland’s Heart Coffee:
Most espresso roasts are a poor representation of specialty coffee. Roasting is really hard, and to roast consistently requires a lot of work. Roasting a coffee that is properly developed and that will extract on your espresso machine in 25-35 seconds is the problem we run into. Most people would blame the grinders, but the biggest impact starts is with your roasting process [sic].
We have a few world-class roasters here in Calgary and, of those, only Phil & Sebastian gets their espresso roast profile right. Most are far too dark and flat-tasting. But roast profiles for filter coffee usually work just as well in an espresso machine; I’ve even had great espresso made from coffees at the cinnamon roast stage. The lesson here is that darker coffees or coffees labelled “espresso roast” don’t necessarily make better espresso.