The invention relates to a method for cooling materials, in particular food, in a cooling apparatus, the cooling being completely or partially carried out by contacting the materials with a cryogenic liquid. Said method is characterized in that the contacting is carried out by means of the injection of two cryogenic liquids, nitrogen and CO. The liquid nitrogen and the liquid CO are injected either separately, into at least two injection points of the apparatus, or by mixing both cryogenic fluids at the injection point. The invention is of use if the apparatus being utilized is a mixing, batch mixing, or grinding chamber, with the injection being carried out into the body of the material in the bottom portion of the chamber.