Tout savoir sur les méthodes de séchage du tabac

Before developing their full aromatic potential and becoming the cigars we enjoy so much, tobacco leaves go through many stages of processing. Among these different processing cycles, drying is the stage that takes place between harvesting and the various fermentation periods. It must make it possible to alter the chemical composition of the tobacco while preserving its intrinsic characteristics.

What is the purpose of the tobacco drying stage?

The tobacco drying process is a crucial stage in cigar manufacturing. It can last from 4 to 8 weeks depending on the tobacco variety and the drying method used. During this period, the tobacco leaves will lose around 80% of their water content and develop their aromas and their flavors.

From the very beginning of the drying process, the chemical composition of the tobacco leaves begins to change. The gradual breakdown of chlorophyll makes it possible for the sugar, proteins, starch, and nicotine present in the tobacco to decompose. In contact with air, the tobacco oxidizes and gradually loses its green color. It first goes through a yellowing phase before taking on its characteristic brownish color. By the end of this process, the tobacco leaves will still contain between 20% and 30% water and will be ready for the first fermentation stage.

The different tobacco drying methods

There are four main tobacco drying methods. The choice of method depends on the tobacco-growing region, the tobacco variety, and the intended use.

Air drying or air-cured tobaccos

Air-curing is a type of natural drying that consists of hanging tobacco leaves on cujes so that they can dry at their own pace. It is the most commonly used drying method among premium cigar manufacturers. In general, this method takes place in wooden barns (Casas de Tobacco) protected by palm-leaf roofs. These rudimentary structures make it possible to regulate humidity levels and ambient temperature while allowing the air to circulate optimally. To encourage perfectly even drying, the workers responsible for this process must constantly adapt to weather conditions. The positioning of the leaves is therefore determined by the position of the sun and the level of humidity in the air.

Recent catastrophic weather events have gradually called this traditional drying method into question. Faced with the significant damage caused by the latest hurricanes, many tobacco producers are now turning to more modern drying sheds, covered with metal roofs and artificially ventilated.

Under ideal climatic conditions, the air-curing method lasts between 4 and 12 weeks. As a natural drying method, it allows the desiccation process to continue to completion and thus ensures a slow oxidation of the plant’s tissues. This has the advantage of significantly reducing the sugar content in the tobacco and resulting in a fully natural browning of the leaves. This method therefore makes it possible to obtain tobacco leaves with lighter flavors and a higher nicotine content. The drying process is complete when the central vein of the leaves is free of moisture.

Sun drying or sun-cured tobaccos

Sun drying is also one of the natural tobacco drying methods. It is mainly used in Asian and Mediterranean countries. As the name suggests, this drying method consists of placing tobacco leaves outdoors and exposing them directly to sunlight. This process can last between 12 and 30 days and produces tobacco with a high sugar content and a lower nicotine level. Sun-dried leaves are also recognizable by their yellow-orange color and their grassy, spicy flavors. They are mainly used for pipe tobacco and cigarette manufacturing.

Direct heat curing or fire-cured tobaccos

Direct heat curing consists of exposing tobacco leaves to smoke, either partially or continuously. It is mainly used in Indonesia. Just like with air-curing, the leaves are hung in large barns, but these have enclosed walls to maximize smoke exposure. Depending on the type of tobacco being cured, this process can take between 3 days and 10 weeks. It produces a strong tobacco with a low sugar content and a high nicotine level. Direct heat-cured tobacco leaves are also distinguished by their smoky, woody flavors. They are mainly used as a blending component in pipe tobacco, chewing tobacco, and snuff tobacco, but can also be found in certain cigars.

Indirect heat curing or flue-cured tobaccos

Indirect heat curing is a tobacco curing method that consists of exposing the leaves to a heat source (hot air, smoke, or steam) indirectly. The leaves are hung in a barn fitted with pipes or ducts that carry heat (around 75°C). This method makes it possible to dry tobacco leaves quickly (within 4 to 5 days) and gives them the characteristic golden-yellow color of cigarette tobacco. It also gives the tobacco a high sugar content and a low to medium nicotine level. Today, these barns use particularly sophisticated techniques that make it possible to program the desired temperature and humidity with the help of computers.

Preparing the tobacco before fermentation

Once the tobacco has been cured, the leaves are destemmed and then sorted according to their weight and size. They are then lightly moistened and placed in bundles of around fifty leaves to start the fermentation process. Before it can be smoked, tobacco must go through several stages of fermentation in order to eliminate the ammonia and other impurities it contains. These steps also make it possible to reduce the amount of nicotine and tar present in the tobacco and refine its aromas.