Abstract: Method of drying a medium for producing a porous matrix from a solution, a paste, an extract, a granulated material or such, where a liquid inert agent is fed into a vessel (5) at controlled pressure and amount through a valve (7), transferring the pressurized liquid inert agent to a mixing vessel (4), said mixing vessel (4) also receiving the solution, such as paste, extract or granulated material, through an inlet valve (10), adjusting the pressure and temperature inside the mixing vessel (4) to desired levels by a release valve (6), upon complete mixing of the inert agent with the solution, the mixture is expanded into a porous matrix and injected into a drying circuit through a drying chamber (3), the matrix thereby being kept suspended in the drying chamber by the flowing drying medium, supplied by the blower (2), the matrix moisture being removed from the mixture through a heat exchanger coil comprising a first heat exchanger (11) where the water vapour is condensed and removed from the circuit and fina