Coffee roasting is a very scientific process that requires a lot of precision. There are a variety of roasts and every coffee roaster defines their own roast levels differently. Large commercial operations usually have darker coffee because it is easier to roast dark coffee in large quantities. Smaller specialty coffee roasters have a bigger variety of roast levels, often lighter roasts which are easier to perfect in small quantities.
The process of roasting actually starts with selecting the coffee, some coffees are better as dark roasts while others are better light. knowing the flavor profiles of the coffee you are roasting is key to the process. Just like bread vs toast while they are the same thing they can have a very different texture and taste. Some breads are better toasted while others are better not toasted at all.
The second thing a roaster thinks of before they roast is what they want the coffee to be, brewed filter or espresso. Filter (drip coffee) is a gentle process letting the water flow naturally to the bottom using gravity. Light aromatic roasts are often better for filter coffee because they often bring out the most flavor from the bean producing a cleaner, sweeter, and less acidic taste. Espresso is less gentle forcing pressurized water through the coffee. Darker bold roasts are often preferred for espresso because the pressurized process creates a more acidic full body flavor giving it a stronger coffee taste.
Hot-Air Vs Drum
There are 2 types of roasters drum and hot air roasters. While it is a heated debate between roasters which is better they each have their own positives and negatives. Drum roasters are slower but roast more evenly. Hot-Air roasters don't cook the beans as evenly but are faster at roasting.
Drum Roasters are basically a barrel on its side that spins while a heat source heats the barrel from the bottom. The spinning process helps heat all the beans evenly. Drum roasting is slower but the roaster has more control over the process.
Hot-Air roasters are a newer technology that shoots hot air all around the bean. The coffee is suspended by the air within the roaster and the hot air roasts the coffee. While it is a much faster process it doesn't heat the bean as evenly as a drum roaster. Hot-Air roasters are usually seen in large commercial operations because you can roast more in a shorter amount of time.
Our roaster is a hybrid Probat 90 kilo is the best of both worlds. This custom designed roaster roasts coffee without a direct flame (like a hot-air roaster) this circulates heat throughout the spinning drum (similar to a drum roaster). We find this process helps roast the coffee evenly and consistently, reliably bringing out the flavors we love about our coffee.
Roasting each batch of coffee can take anywhere from 10-20 mins depending on the type of roast, quantities being roasted, and the roaster being used. Perfecting the art of roasting takes years of experimentation to master. In our next part we will talk about the roasting process itself and the differences in coffee roasts.