Last time around (see part one here), I wrote an introductory look at the process involved in processing coffee, from the farms and trees to the green beans in 150 lb. bags – large bags with markings from far away places. Leaking out from small holes in the bags are hard, bluish, greenish or yellowish beans. The smell of burlap hangs in the air, soon to replaced by the aroma of fresh roasted coffee.
Early in the morning, I go to the roasting house, fire up the propane shop roaster, throw a couple of logs in the woodstove and have a cup of coffee while checking the orders and planning the day’s work. The roasting house is a cedar log building in a small rural Acadian village. This would not be considered a typical situation in the coffee world. There is a lot of coffee roasted every day and most of it is done in large factory situations located in giant industrial parks near heavily populated areas. I am happy to be drinking my coffee next to the wood fire instead of in a car crawling through commuter traffic.
Coffee is usually roasted before being consumed. There are some countries where green coffee beans are ground with cardamon seeds and then steeped like tea before being drunk but it isn’t what comes to my mind when I need a cup of joe. The reasons that coffee beans are roasted is the same reasons that food is cooked, that being to make it taste better and to make it more digestible (when not thinking about coffee it is usually food that is on my mind). Some common foods are not edible when raw or not digestible, during cooking heat will cause chemical changes, breaking down or converting unwanted natural components. The same for taste, a raw potato might be edible but is starchy. When it is cooked it becomes sweet, and if it is pan fried, it ‘browns’ as sugars are caramelised. Coffee is similar, I guess my job is that of a ‘bean browner’.
Soon the roaster is hot and it is time to toss in a pail of green beans. Not much happens at first, time to fill out a roasting log, and pull a shot of espresso. In a few minutes the beans start to look a bit yellow brown ( there is a tiny window in the roaster that serves little use other than to make people exclaim ‘oh look! the beans are going around’). The heat is drying out the beans and driving the water off. At this point the beans smell like straw. As the process continues the beans get hot enough that the remaining water inside them boils and causes them to make popping sounds and puff up, much like pop corn.
This stage of the roast is in what is called ‘first crack’ and the beans at this point get larger, are light brown and have very little smell. Soon the starches in the beans are converted to sugars. The coffee starts to smell sweet, and the ‘second crack’ stage begins accompanied by the crinkly sound of crumpled cellophane. The coffee soon takes on the typical coffee smell we associate with a light roast, the surface of the beans become smooth, and the crack of the bean that runs up the flat side, opens up a bit. How this is observed? There is a little scoop called a ‘tryer’ that sits in a hole in the roaster, it can be used to remove a small sample of beans to look at and smell. The tryer is hot so if you see a roastmaster with burn marks on his face you now know why.
If is to be a light roast coffee (about 14 - 17 minutes from the start) the beans are dumped into the cooling tray and room temperature air is drawn through them to stop the roasting process. Light roast coffees are sweet and bright or acidic. They retain the particular characteristics typical to the beans origin. Coffees with fine and delicate character are usually roasted light. The delicate floral and citrus notes would disappear fast if the coffee was roasted dark.
If a medium roast is desired the coffee is left in the roaster longer into the second crack until it reaches a higher heat. At this point of the roast things happen fast. The sugars in the beans start to caramelise and new and different tastes and aromas are being created. The smell of the coffee us now spicy and caramel-sweet, time to dump and cool the beans for a medium roast. These beans look medium brown with no oil on the surface, if the beans were left in a bit linger the oil from the beans would start to come to the surface and the roast would be less sweet, less acidic, and become slightly bittersweet. This would be a Dark roast (mi-noir). At this point of roast the original character of the bean is less pronounced and what is tasted is to a degree imparted by the style of roasting.
One further roast can be done, the Black (noir) roast, to some this is sacrilege to others it is heaven. By Black roast I do not mean the burnt, charcoal, thin and bitter tasting, but the bittersweet, smoky, ‘corsé’, coffees preferred in some countries. ‘Common roasting knowledge’ usually dictates that one uses the cheapest beans for the darkest roasts as what is being tasted is not the bean but the taste of the roast. I follow the opposing view, it takes a bean with exceptional or assertive character to survive that much heat and still be able to come through with its own identity. Beans such as Kenyan and Haitian can hold their own. The difficulty is to find the correct finish point. As the oils come to the surface of the beans they touch the hot drum of the roaster and they smoke, this will perfume the coffee. The difference between a good black roast and charred coffee is only a matter of seconds not minutes.
You will notice that I am not using the common terms of description for the degrees of roast. Scandinavian roast, Cinnamon, roast, American roast, City roast, Full city roast, Continental roast, Viennese Roast, Fench roast, Italian roast, etc., etc., They might sound colourful but there is not much general agreement on these terms, ‘Is the Italian roast darker than the French roast?’ and such. I like the terms Light roast, Medium roast, Dark roast and Black roast. I think of these as more a description of the taste I want the coffee to have than the actual colour of the bean.
There is a more accurate technical way to quantify the darkness of the bean but these numbers mean little to the average coffee drinker. As the roasting of coffee progresses through different stages the beans go through various chemical changes accompanied by changes in the taste and aroma. Each different origin of bean responds in its own way to the roasting process. A proper light roast, (where the coffee is sweet and showing none of the grassy sourness of under roasted beans), occurs at slightly different temperature and time for each bean. I find that the method of determining the finish point that serves my temperament best is to take a ‘craftsman’s approach’. For this it is necessary to know both the technical aspects of roasting and the chemistry of the processes but the final determination is based in not only on the time/temperature of the roast and the physical look of the bean but more importantly by the smell of the bean. This might seem a subjective way to do things but the sense of smell is very accurate. There is a close connection between ones sense of smell and taste where there is little connection between taste and sight and taste after all is what we are interested in.
The Petrocini in our shop, just finished dumping beans and the cooling cycle begins.
In front of our microroaster, a very capable Petrocini.
These descriptions applies only to small ‘micro-roasters’. The coffee industry in general has a much more efficient approach to coffee, often using giant computer controlled roasters that can process as much coffee in a few minutes as a small farmer can grow in a year. The advantage of computerised coffee roasting by trained technicians is consistency. Name brand coffees need the taste of their blend to be the same for each and every can. The micro-roaster might place a higher value on the rare and unusual coffees whose excellence might be associated with a single estate coffee from a specific harvest year. Thinking with my stomach again, the comparison might be similar to a talented chef preparing a meal for a handful of guests using the finest seasonal ingredients available (taste taking priority over conformity) and that of food prepared in a factory setting to consistent standards.
There are several different methods used in coffee roasting, from traditional drum roasters to modern fluid bed units as well as different theories on roasting styles, from very fast ‘high yield’ roasting to very slow ‘Brasilian’ roasting and even a ‘twice-roasted’ technique is used by some. Personally I like ‘old fashioned’ natural coffees with their full taste and low acidity and use a drum roaster that draws hot air through the tumbling beans as they roast. This enables an even roast from the hot air with the ‘traditional’ flavours of drum roasting. Fluid bed roasting uses heated air forced through ‘floating’ coffee beans which gives the coffee a clean finish and a ‘bright’ taste. The ‘style’ or approach of the roastmaster as well as the method of roasting and the type of equipment used will greatly influence the taste of the coffee.
As soon as I have finished roasting and cooling the beans they are packaged and sent out to customers. Other beans are put into 5 gallon plastic pails when still warm and sealed with a lid for the next days use. One of my greatest pleasures is to remove the lid the next morning and stick my whole face in the pail of beans and breathe in deeply.
Next article Part 3- Blending Coffee, and in the meantime I will go back and stick my head in a pail of beans... ahhh.