Tobacco Curing Process
Returning to the broad topic of the leaves, which we discussed in a previous text, we will now focus on the first of the three processes -curing, fermentation and aging- that take place once the harvest is over.
The curing of the leaves is a process in which important biochemical and, above all, physiological transformations occur, some of which are internal and therefore not visible, while others can be observed with the naked eye. This process is also known as drying, but in reality, it would be applicable to the curing that is carried out artificially, because in the manual, the biochemical transformations of the leaves predominate over the loss of water.
Among the most significant changes that occur in the leaf are: replacement of the green color of the leaf by yellow or orange, loss of a high percentage of the leaf's water, reduction in thickness, conversion of proteins into amino acids, oxidation of polyphenols, increase in mineral and nitrogenous substances and decrease in nicotine content.
The process can be carried out by different
methods, the use of which depends, among other factors, on the climate and the
traditions of the place; in all of them, the aim is to achieve adequate control
of the conditions to obtain a quality final product. The most commonly used
methods are:
Air-Cured
Natural air is the essential element of this
method of curing, so the constructive characteristics of the places where it is
done must be adequate to ensure the conditions of temperature, humidity and
speed to achieve the expected result. During this process, the tobacco is hung
in unheated, well-ventilated spaces to dry naturally until the leaf reaches a
medium light brown color, which generally takes between 40 and 50 days.
Fire-Cured
This process is a variant of air-cured, in which, after the tobacco has been in the dryer for three to five days, different types of wood are burned under the leaves. This combustion accelerates the drying process of the leaves and imbues them with the flavor and aroma characteristic of the type of wood used.
Sun-Cured
In this curing process, the leaves are hung
directly exposed to the sun. It is one of the most commonly used in Eastern
countries, since their climate is appropriate for it. Sun-cured tobaccos are
very aromatic and are therefore preferably used for pipes and chewing, or used
in small proportions in the cigar blend as they provide a lot of aroma and
flavor.
Flue-Cured
This method consists of using a system that allows automated and computerized control of temperature, relative humidity and air speed. This method is applied for the leaves that will be used as cigar wrappers and for the tobacco for cigarettes and bite.
