Concentration of wet tobacco extracts

A method of manufacturing a concentrated tobacco extract for an aerosol-generating article, the method comprising:

• preparing a natural tobacco material, wherein in the step of preparing the natural tobacco material, the natural tobacco material is not subjected to any treatment adapted to alter the pH of the tobacco;
• providing the natural tobacco material;
• heating the natural tobacco material to a temperature and for a time such that volatile species are released from the natural tobacco material, the volatile species comprising nicotine, wherein the heating the natural tobacco material comprises heating the natural tobacco material in a flow of inert gas or in a flow of a combination of an inert gas with water or steam or heating the natural tobacco material under vacuum;
• collecting the released volatile species and forming a liquid, naturally derived tobacco extract comprising the collected volatile species, a polyhydric alcohol, and at least about 40 percent by weight of water;
• and
• heating the liquid, naturally derived tobacco extract to evaporate at least some of the water and obtain concentrated tobacco extract, wherein the naturally derived tobacco extract is heated to a temperature and for a time such that a water content in the naturally derived tobacco extract is reduced by at least about 60 percent.