Abstract: A method of treating biologically affective particulate material includes adding absolute ethyl alcohol to the particulate material and heating for sufficient time to kill organisms present, but insufficient time to cause breakdown of particulate material. The method is particularly adapted for the treating of sodium ascorbate, a heat sensitive material. Preferably absolute ethyl alcohol is used, to help minimize the presence of water, which can cause decomposition of the sodium ascorbate. In preferred applications, heating is to a temperature within the range 100.degree.-130.degree. C., and for heating cycles of no greater than about 2-10 minutes, with a cooling interval between successive heating cycles.