The Art of Roasting and Grinding Coffee

Roasting is the first step to extract the aroma of coffee beans. The best roasters adjust the temperature of the roasting machine to create a variety of flavors and colors. A medium roast produces a smooth coffee with a faint woody aroma; the European style is very fragrant, while the Italian style is dark and intense, leaving a lasting taste in the mouth.

Green beans, packed at the plantations and purchased by importers, have no flavor or aroma; but between the fresh green beans just harvested and the brown beans ready to enter the factory, many chemical and physical changes occur, making the role of the roasters as important as that of the growers. Coffee roasters have a huge responsibility. When roasted correctly, good beans become magical coffee, but if not, they are just waste. That is why top companies always do test roasting before deciding on official grinding.

In shops where coffee is traditionally roasted, the roasting machines are impressive creations, like old steam engines with pipes, levers, and temperature controls. Roasting takes about 12 to 20 minutes, depending on the machine and the type of bean, at temperatures ranging from 180 to 250°C. The coffee beans turn light brown as they are heated, changing their original pale green color to brown. They also change in size and lose moisture. Toward the end of the process, essential oils begin to release their aroma.

Although roasters are equipped with vents to let the roaster know the roasting level or stop the roasting if necessary and check for a sample, skilled roasters work mostly by ear. The roasted beans begin to “sing”: they crackle and pop. When they hear this sound, experienced roasters know it’s time to turn off the machine. They then open a chute and the hot beans are dumped into a large, ventilated vat that cools them instantly.

The art of roasting is highly refined, reflecting personal taste and preference. Some roasters warn against over-roasting coffee, as it will deodorize it. There are many different opinions when it comes to the proper roasting temperature for the world’s best coffees. For example, there are two schools of thought when it comes to Kenyan coffee beans. Some believe they should be roasted over-roasted to reduce their natural acidity, making them sweeter; Others, on the other hand, believe that a light roast enhances the flavor and brings out the innate characteristics of the coffee. The “dark roast” seeks harmony and consistency, the “light roast” is a sense of innate qualities, even at the risk of shocking the uninitiated. Bruno Saguez, one of the most accomplished roasters in Paris, notes that connoisseurs are increasingly appreciating flavors that are different from what they are used to. At his shop near the Pompidou Center, where an extensive selection of the world’s finest coffees can be sampled, Saguez roasts coffee every morning in front of his customers. It’s a delicate art, requiring intense concentration and inspiration. Saguez is one of the few roasters in France to offer a range of roasts, from light, to golden, to almost black. And he is also the only one who brings a common thread to different roasts – great subtlety. For example, he adds a little Mexican Maragogype to a light coffee to increase its acidity, and a French light (a rather light brown) is more aromatic and aromatic.

At Piansa, Florence (Italy) (see photo above), as elsewhere, when the lid of the roaster is opened and the hot beans dance, the room is immediately filled with the magical, lingering aroma of freshly roasted coffee, the same aroma that warms the kitchen where the coffee is roasted in a pan on the stove, the same aroma that is also created by the family charcoal ovens – the coffee roasters that were still sold in the early 1980s. In Belgium, where the average person consumes three cups of good coffee a day, roaster Etienne Knopes, whose father and grandfather were also roasters, boasts a loyal and discerning following.

The range from light to very dark is full of subtle nuances that cover all the official colour terms: light, medium, light French (the most common roast in France today), European (dark brown), French (very dark roast, ironically increasingly rare in France) and Italian (nearly black). Light roasting brings out the rich aromas and mellow organic components. This has long been popular in Germany, Scandinavia and eastern France. Light roasts are also used in Türkiye and Greece to make “Turkish coffee”. On the other hand, longer (i.e. more thorough) roasting produces dark, dark beans that are sweet and sometimes bitter with more flavour than “traditional” coffee. Very deep roasting (to create a foam for espresso) is the rule in Italy, northern and southern France and – in an even darker, oilier style – in Lebanon and some Middle Eastern countries, where the taste for Turkish coffee is very strong. The difference between lightly roasted and well roasted coffee is as great as that between cooked and raw food or black and green tea.

Incidentally, it is interesting to note that recently in Italy and the United States, there have been roasters promoting the quality of their “wood-roasted” coffee. No one can deny that this – with its organic and natural qualities – is very attractive. But since the coffee bean became coffee, that is, for (at least) the four or five centuries that these beans have been roasted, the work has always been done using metal heating devices because nothing better has been discovered. The source of heating – wood, gas, or electricity – has no effect on the quality of the roasting.

Moreover, there is no reason why you should not try roasting coffee yourself in your own kitchen. You will need a heavy, old-fashioned pan, a wooden spatula to stir the beans (the colour should be uniform), a heat source (any kind of stove will do) and – if you are a beginner – some cheap coffee that will not disappoint you if you do a bad roast. Practice makes perfect and it takes time to learn how to roast coffee: the beans should crumble when squeezed, but should not burn. The best way to roast is to start with a low heat and finish with a high heat. When the beans start to sizzle, they should be poured out immediately into a cool place. Alternatively, use a small electric roaster, which is now widely available. However, homemade coffee will never be as good as that made by professionals who have the skills and experience to roast coffee properly. And it’s also worth noting that roasted coffee must be left to rest for 36 hours before grinding, so the only advantage that home-roasted beans might have is lost: absolute purity.

Collected.