This invention concerns a method for the manufacture of a granulated aerogel (1) from a precursor (2), comprising the following steps: mixing the precursor (2) with a synthetic solvent (3) and a hydrolysis agent such as water, and if appropriate a catalyst (4), to obtain a gel, granulating the resulting product, in particular by cutting a jet of said gel, to produce granules, maintaining the granules in contact with the synthetic solvent (3) and the hydrolysis agent, washing the granules by adding a washing solvent to extract in particular the hydrolysis agent and, if appropriate, the catalyst (4), drying of the granules to extract the synthetic solvents (3) and/or washing solvents by sending them supercritical CO2 in excess, the steps of granulating, maintaining, washing and drying being carried out at a pressure higher than that of the critical point of CO2, and these conditions being maintained between these steps. The present invention also concerns an installation specially configured to implement the method according to the invention.