Abstract: Tobacco is expanded by cooling the same to a temperature of about 30.degree. F. or less and subjecting such cooled tobacco to a subatmospheric pressure in a vessel. CO.sub.2 gas is then introduced into the vessel and contacts the cooled tobacco to impregnate the tobacco with CO.sub.2 gas as pressure in the vessel is brought to substantially atmospheric pressure. Subsequently, the cooled CO.sub.2 impregnated tobacco is subjected to conditions whereby the CO.sub.2 in the tobacco is removed and the tobacco is expanded. Typically, the CO.sub.2 impregnated tobacco is introduced into an expansion tower wherein it is heated to increase the volume of the CO.sub.2 and to expand the tobacco in size.