Matt Bolinder, owner and roaster at Speckled Ax, was featured in article about wood-roasted coffee in the latest issue of Imbibe magazine.
For Bolinder, wood choice is about controlling this highly specialized process. “The type of wood is important for the rate of burn and how quickly I can manipulate temperature,” he says. “I can’t go from zero to full gas in a second like most roasters, so I compensate by using different types of wood. Ash takes off quickly and with it, I can increase temperature fairly quickly. On the other hand, red oak takes longer to catch and start throwing heat, but its large pieces hold the temperature.”
The article isn’t yet available online but there is a copy behind the counter at Speckled Ax which you can take a look at. Imbibe has posted a short list of coffee shops in the US that feature wood-roasted coffee.