The filling capacity of tobacco is increased by establishing a body of water-moistened tobacco in a bed in a hermetically sealed chamber. A partial vacuum is applied to the bed to remove occluded air and the tobacco is contacted with vapors of a compound having an atmospheric pressure boiling point between about -10 and +80* C., the temperature of the tobacco during contact being maintained at or below the boiling point of the compound at the prevailing pressure, whereby the tobacco is impregnated with the compound in the liquid state by condensation. The impregnated tobacco is then equilibrated, and a drying gas at a temperature between about 40* and 80* C. is passed through the bed to remove a portion of the moisture and the impregnating compound as vapors. A hot gas at a temperature above about 90* C. and more than about 18* C. above the boiling point of the compound is then passed through the tobacco to expand it.