From Green to Caffeine
The transformation from green coffee beans to something drinkable is quite miraculous, in many ways comparable to grapes becoming wine. There are numerous similarities between coffee and wine, however the process of making drinkable coffee is drastically different from wine making. Roasting the beans is analagous to the fermentation stage of wine making; this is where the magic happens. The process itself is rather simple, though it depends on many variables, such as bean type, roast level preferred, and how the coffee is intended to be brewed. A seemingly minor change in one of these variables can have a major impact on the end product.
For the unfamiliar, roasting coffee is simply turning green beans into brown beans by means of some heat source. Rather than a technical description of the process I’ll focus on a general outline of how this works. The heat source can be anything, for instance, simply roasting beans in a skillet works, though the results are far from remarkable. I’ve roasted beans in everything from a skillet to a convection oven to a homemade contraption made from an old pressure cooker. With practice, the results can be quite good with some of these methods, though consistency from roast to roast can be a challenge.
One of the most important aspects of roasting coffee is knowing when to stop. If the beans are under-roasted the coffee can have a very grassy taste, while if you over-roast you simply end up with charcoal. You can determine roast level by visual inspection or temperature, but one of the most important methods for determining roast level is to listen to the beans. As a result of chemical reactions, the beans make a cracking sound when they heat up. If roasted long enough, there will be a first and a second crack. The first crack signifies what is known as a City roast, while just before the second crack signifies a Full City roast. French roast is carried all the way through the second crack until the beans are quite dark and oily.
You might ask Which roast level is the best? Well, that depends (a lot) on the type of bean being roasted and how you want the coffee to taste. Lighter roasts have the potential to bring out more of the bright, flowery tastes in a coffee while a darker roast might bring out the deep, chocolate like flavors. Some beans are very forgiving with respect to roast level, while others will only taste good on one end of the spectrum.
Making a great cup of coffee is an art; an art which we sometimes take to the extreme. For instance, we make our coffee in this vintage La Pavoni lever espresso machine! It’s not a pretty machine, but there’s something about the manual labor involved with using this machine that makes the end result that much more enjoyable.
So there you have it; a little insight into roasting fresh coffee.