A method and plant for cooling a mixture of concrete, includes: loading in a hermetically sealed tank a given quantity of ingredients to form the concrete, the ingredients including a predetermined quantity of water; regulating the pressure in the tank to obtain a transitory degree of vacuum in the tank; regulating the pressure inside a hermetically sealed condensation chamber to obtain a basic degree of vacuum in the condensation chamber that is greater than the transitory degree of vacuum, such that the pressure in the condensation chamber is lower than the pressure in the tank; operatively connecting the tank and the condensation chamber to substantially equalize the internal pressure in the tank and in the condensation chamber to a resulting degree of vacuum and to cause at least partial evaporation of the water from the tank towards the condensation chamber to lower the temperature of the ingredients in the tank.