Thursday, February 12, 2009

The Sweet Smell of Coffee Roasting...


One of the most important steps in the journey from bush to brew is roasting. An over-roasted bean is a tragedy that happens frequently in the coffee industry. You can often spot it by the charcoal flavor in your cup or an excessive oiliness on the outside of the bean before grinding. Some fine beans can hold up to a darker roast; others lose their flavors and nuances completely. Any dark roasted bean should be rushed to brew, as any oils that form on the outside of the bean can go rancid quickly once exposed to oxygen.

Back to the roasting process...a large-scale roaster (or even a small portable home roaster) may be used to roast the green beans so that they may be brewed. Before roasting green beans are typically greenish-brown and have a somewhat grassy smell. Roasting causes many complex chemical reactions to occur, much like baking.

At Ashley & Cooper Coffee Roasters, we use a Diedrich IR-12, which has a 12 kg or 30 lb maximum capacity. During roasting, there is a distinctive aroma released that pervades our facility...that of roasted chocolate, with a slightly sweet perfume. If you spend any time in our facility while roasting is occurring you will leave smelling of roasted coffee...it is that pervasive!

Each bean must be test-roasted and cupped to find the perfect level of roasting. This is because every bean has a different size, moisture content, density, and weight, depending on origin, screen-size, and whether it is a special bean such as the Peaberry, which is a round mutation with a denser bean. When a fine specialty coffee is roasted in just the right way, the difference in the cup is indescribable.