Abstract: A tobacco expansion method is provided whereby cured tobacco is first moistened with a humectant solution, as is conventional in the industry, to increase the resident liquids thereof. Next, the prepared tobacco in shredded form is placed in a sealed chamber and the chamber evacuated to vaporize a portion of the resident liquids. Next, ethyl alcohol vapor is allowed to enter the pressure chamber below 70 mm (Hg) absolute to prevent a water-ethyl alcohol azeotrope from forming. Thereafter, a hydrocarbon vapor, such as n-pentane vapor, is directed into the chamber and the pressure restored to atmospheric. The n-pentane vapor diffuses into the cellular structure of the tobacco with the assistance of the ethyl alcohol, whereafter the tobacco is heated and the n-pentane and ethyl alcohol acts as a propellant to expand the tobacco.