Coffee Know-how

Roasting coffee: between art and science

The aromatic and taste nuances that ultimately dominate in the cup depend on many factors. In addition to the quality and variety of the coffee bean and the preparation method (brewing process), the method of roasting has a decisive influence on the taste of the coffee. Put simply, roasting is a heat process that transforms coffee into the aromatic, dark brown beans that we know and love. However, the process from the coffee bean to the finished coffee is somewhat more complicated. An important step in the process - in which the potential of a coffee bean comes to its full expression - lies in the perfect roasting.

Everything begins with green coffee

Whether from Brazil or Indonesia, whether Arabica or Robusta - at the beginning of every coffee there is a cherry-like fruit: the coffee cherry. As soon as the fruits are picked from the coffee tree, they are dried. The unroasted bean is known as "green coffee" because the bean actually looks greenish (but depending on the type of cherry, it can also be yellowish-brownish) when dried and unroasted. The beans are stored raw, in a state in which they can be kept without loss of quality and taste. A green bean differs from a roasted bean mainly in smell: surprisingly, it does not smell like coffee, but rather like freshly mown grass or green tea.

Ripe coffee cherries: Inside this drupe you can find the coffee bean.

Our colleagues at Blaser Trading enable the import of the best green coffee, which can be traced back to the respective coffee cooperative. This high level of quality and transparency is only possible thanks to the partnerships we have maintained over many years with cooperatives and coffee farms in almost all countries of origin.

The roasting process: what happens to the bean

As described at the beginning, the perfect coffee is the result of a combination of factors. A careful roasting technique is an important part of an optimal taste experience in the cup, as the roasting process brings out the aroma and aroma properties that are locked up in the green coffee beans.

Roasting causes chemical and physical changes as the beans are continuously brought to high temperatures. The green coffee beans are heated between 180° and 210° degrees in coffee roasting plants. When the beans are filled into the roasting drum, the temperature initially drops to around 90° degrees. Afterwards, depending on the roasting profile, the temperature is constantly increased. The roasting profile created, i.e. the progression of temperature and roasting time, has a considerable influence on the later taste, aroma and balance of the coffee. At our plant, the beans are roasted between 14 and 25 minutes. It is therefore the interaction of time and temperature that determines the degree of roasting from light to dark.

Wenn die Bohnen den gewünschten Röstgrad erreicht haben, werden sie rasch abgekühlt, um den Röstprozess kontrolliert und zügig zu beenden. Geröstete Bohnen riechen zuerst erstaunlich zart und entwickeln erst nach einigen Tagen den typischen Kaffeegeruch. Da während des Röstprozesses Feuchtigkeit, welche in der Bohne gespeichert ist, verdunstet, wird der Kaffee durch die Röstung bis zu 20 % leichter. Geröstete Bohnen sind bissfest, und nach einer kurzen Zwischenlagerung bereit, gemahlen und gebrüht zu werden. Andernfalls ist es wichtig, dass die gerösteten Bohnen schnell luftdicht verpackt werden, damit das typische Aroma nicht entweichen kann.

In fact, it takes years of experience to be able to "understand" the beans properly as a roaster and make decisions in a fraction of a second. It is therefore not surprising that the difference between a perfectly roasted coffee and a ruined batch can be a matter of seconds. In coffee circles it is therefore often said that roasting is both an art and a science.

Roasting degrees and coffee blends: from light to dark

As a family roastery, we are proud to have a wide range of roasting mixtures in all roasting grades. We generally differentiate between three different roasting grades: light, medium and dark roast.

The gentle cooling of the roasted coffee beans by the circulating air is an essential part of drum roasting.

Light roast

Light roasted coffee beans are light brown. They have a fruity, sour taste. A lightly roasted bean also offers more original aromas that come from the soil, weather conditions and other plants grown around the coffee plants. Terroir Panama benefits from this principle thanks to its light roast, as the coffee bean is cultivated in volcanic soil, resulting in an incomparable complexity of flavor in the cup. Light roasts are particularly suitable for filter coffee, where the increased acidity and fruitiness are shown to their best advantage.

Medium roast

Compared to light roasted coffee beans, medium roasted coffee is slightly darker in appearance. The beans also usually have a more balanced flavour and less acidity. Rosso & Nero is a typical representative of medium roast: mainly used as café crème, but also as espresso or milk coffee, this coffee comes into the cup with an extremely balanced taste.

Dark roast

This degree of roasting gives the coffee bean a shiny, oily appearance with a less acidic taste. Dark roasted coffee beans are heated to about 210° degrees just before the "second crack". The taste can be slightly bitter or smoky due to the roasting process. Dark roasted coffee tends to have a roasted flavour - fine notes of dark chocolate, tobacco, or cloves - which overshadows the coffee's original taste. Many coffee drinkers assume that dark roasted coffee has a higher caffeine content, but this is not true. This is ultimately determined primarily by the type of bean and the brewing process. In our range we have a perfect espresso coffee in the form of Marrone, which has a lot of sweetness and mild acidity due to its dark roast.

Ultimately, it is the individual taste of the coffee drinker that determines which roast is preferred. We invite you to try our different coffees to find your favourite.