In this paper has been studied a plant for the cryo macerating of the grapes by direct injection of liquid CO2. On the base of indications of different oenological industries have been examined the problems rising under limit conditions for the considered plant, and experimental tests have been performed. By a system of data acquisition the temperature distribution has been detected along the pipeline, inside it, where the mixing of liquid CO2 with grape juice happen. By different experimental tests has been detected a fluctuating course of the temperature inside the pipeline. It is due to the turbulent regime and at the portion of CO2 that it doesn't exhaust thermal exchange inside the considered pipeline. In order to obtain a better understanding of the phenomena related at these problems, some simplified models have been considered and simulations by means CFD codes have been performed and results compared with experimental data obtained. The obtained results are an important indication for following developments of optimization of such types of plants.