90% of the gum is produced naturally through the process of gumming by the two sub-Saharan species acacia Senegal and acacia Seyal. In this case, sap is produced spontaneously by the plant in response to temperature changes or to eliminate pests. The tree then begins to exude a sticky substance to repair the broken bark. This substance can be secreted as a result of wind, drought, transpoarabinogalactan (AGP) silica particles with a globular or branched structure replaced and carried by the wind, human cuts, scratches from wild animals, insects and parasitic plants, and other factors. In essence, the rubber protects the tree from evaporation, which is detrimental to its survival. This process makes this material feel even more natural because it is extracted in a completely natural way.
Tapping is a technique that involves cutting with a knife a strip of bark 2 to 3 cm wide and up to 1 m long, divided transversely at the base of a branch and pulled upward by hand as much as possible. This tearing of the tissue leads to the formation of a scar bulge at the edge of the wound, from which the gum exudes about three weeks later. Through this process, balls the size of a fist can be obtained. Exudation is most common in October, November and December, when trees lose half their foliage. Six to eight harvests are made each year, and the production season usually ends in March or April.
The side of the incision on the branch should be changed annually, with a maximum of four cuts around the branch, after which branches should be changed. Four to ten branches are used each year, depending on the size of the tree and its degree of branching.
In general, wounds on the trunk, and thus secretion of sticky latex, are more common in mature or old trees with drier bark. Acacia gum production increases as trees age or grow in harsh conditions, such as nutrient-poor soils or extreme drought.
Freshly secreted bark gum is soft, but it hardens quickly in the open air, taking the form of irregular, rounded flakes of light or amber color. At this point it is ready to be harvested, purified and sold. It is also available in the form of white or yellowish-white flakes, granules, crystals or powders, as well as as a dried and spray-dried substance.
