The Roasters Realm
Keeping the Art in Roasting
By Mauro Cipolla

One often hears that coffee roasting is a simple process: Open a burlap sack of beans, empty the contents into the hopper of the roaster, turn on the heat of the roaster, watch the green coffees develop through their roasting stages, open the release door of the roasted coffee. Done.
   Congratulations. You are now an accomplished roaster and can open up for business. Right?
   Well, if we all listen to those who sell us the latest computerized roasters that supposedly allow us to be master roasters overnight, or at most with a few introductory lessons, then yes, you can.
   Alas, it isn't that easy. Anyone can literally roast coffee beans according to the elementary guidelines above. And many are doing just that.
   But the real point of the profession is not to push a button, stand back and collect money. That is merely "cooking" a batch of green coffee by applying heat. The real point has to do with a process of education that can last a lifetime. In this process the questions are more important than the answers.
   As I see it, the most important question is: How do we plan, study, evolve and research for a unique roasting flavor--our very own signature--and then keep it consistent over time so that it can deliver the results that consumers expect?

Conserving Heritage
In roasting, there is a subtle interplay of tradition and innovation. I have been roasting coffees now for (I hate to admit this, but it is the truth) almost 20 years. I learned how to roast from people with three generations of experience in Italy, first on a wood roaster, then on gas flame roasters.
   Was the roasting process suggested to me as simple back then by my mentors? No. Did the experience they shared with me help me get started in a great direction? Absolutely. Did I learn how to roast and blend a good product back then? Yes. Did I know as much then as I do now? No. Is my product better today than it was when I first learned how to roast? Yes.
   The whole point of education is to improve. Conserving tradition is part of that process, but often the best way to honor a tradition is to change it, just as it was itself a change from some earlier way of doing things. The key is to know what you are doing, and why.
   We all accept that specialty coffee is better now than when I started. Part of the reason why is that many of us have distilled, rather than rejected, the wisdom of the past.
So why would an already tested product be better today than 20 years ago? I think there are five basic reasons:

• We have improved our green coffee buying processes;


• We have improved our green coffee storage control as appropriate to our roasting cycle needs;


• We have developed and modified our equipment to meet our very own standards of roasting cycle processes by implementing our very own quantities and qualities of heat transfer and timing inputs;


• We have learned how to modify the roasting cycle to keep our product consistent as atmospheric changes occur (absolute barometric pressure, air temperature, humidity and other climatic conditions);


• We have learned how to control and modify our blends of roasted coffees, despite variations in the nature of green roasted products with each delivery.

   Today, having learned how to control all of these variables and more, our job is pretty simple, until nature or atmospheric conditions change on us again. Then we will have to go back to the drawing board and reshape our assumptions and processes.

Choosing To Roast
As I mentioned above, each of us has a choice to make. Do we wish to simply "cook" green coffees, or do we wish to be known as consistent roasters who produce fine products that are enjoyed by many, win tasting competitions and deliver a signature of flavor that is hard to copy by others?
   In order to decide which path to take, we must first understand a few simple elements about the roasting process.
   Roasting is one of the most important variables in the coffee supply chain. Through its revolving endothermic and exothermic exchanges, the chemical composition of coffee changes, organics are lost and new substances are formed. Added together, these changes give us a particular aroma and flavor in the roasted product. Additional roasting transformations cause a loss of moisture content, an alteration of bean density, a change in the capacity for water extraction, a physical/structural change and an alteration in appearance, which affects both the color of the bean and the amount of oil on the surface.
   Most of these transformations are helped along by the production and formation of carbon dioxide from within the center of the bean structure. A gas present as a by-product of organic decomposition, carbon dioxide, with its high internal pressure, calls for a particular control over its formation and decomposition. That control, dictated by the chosen roasting cycle relative to amount of heat applied, time of application and cooling stage type and timing, is responsible for various cell-structure stretching and explosion mechanisms that work in conjunction with the chemical composition changes of the beans, not only during the roasting process but even after it is completed.
   Thus it is the control of the formation and decomposition of carbon dioxide that is of interest to us artisan roasters.
   To accomplish this task we must design our own system to respond to several imperatives.
   First, we must find our very own signature type of heat to be applied in the roasting process. What type of heat is predominant in our roasting machines? Do we have more radiant direct heat, or more conductive indirect heat? What about convection heat? How much of that do we have pre-engineered and designed into our roasters?
   Next, we must understand how our units work and how (or if) we intend to modify them to give us more of one type of heat versus another.
   Next we must ask ourselves how our units operate relative to temperature control over time.
   The quality of bean development through its various layers is largely given by heat volume and heat time, which also determine the end result. For instance, a prolonged roast would result in a bitter, non-aromatic and dried-out bean. A too-brief roast would yield metallic, astringent, greenish underdeveloped coffee flavors.
   Some roasters who are after high-yielding coffees will opt for the very fast roasting cycles. This is not a good practice, in my opinion, and especially inapplicable to espresso. In this example, roasting times are clearly dictated by reasons not related to flavor profile. They are related to money.
   We must also control the proper upkeep of the equipment. If we do not, we risk fires, bad-flavored coffees and inconsistency in the development from batch to batch.
   Next, we need to control the temperature and humidity in our storage areas, as this type of control will dictate moisture levels and temperatures prior to roasting. This will directly affect the end result bean size, moisture, density and flavour.
   Lastly, we need to control our cooling cycle so as to decide if we wish to opt for the dry-process cooling, for the wet-water cooling or for a mixture of the two styles. Once we have decided on a style of cooling process, we need to decide cooling temperatures and the final holding temperatures of the beans. This stage is very important in preserving or losing the aroma of our beans.
   I have not even begun to mention the principles for purchasing green beans, the differences between roasting before or after blending, and various techniques to modify the blends as our ambient environment undergoes changes.
   These techniques are very personal in their applied methodology and are difficult to explain in detail. But I suspect you get the idea: Roasting is not simple.
   Nor should it be. Involved in any great endeavor is frustration and toil. But there is also satisfaction. By opting to roast rather than cook coffee beans, you will partake in this satisfaction, and it will show in your final product, and in the satisfaction of your customers.

   Mauro Cipolla is the founder of Caffé D'arte in Seattle, Wash. He can be reached through the company's Web site at www.caffedarte.com.