To decrease the oxidation of the liquid and to increase the extracted quantity thereof from the solid part, it is presented a method for processing a crushed vegetal material (14), which has a solid part (16) and liquid part and is placed inside a container (10; 10p), comprising preferably the steps of(i) injecting gas inside the container by making the gas get in through the lower part of the container where in use there is the crushed material so that the gas dissolves in said liquid;(ii) decreasing the gas pressure inside the container.